G1, G7 Ballistics Coeficient?
- Thread starter Buzzsaw
- Start date
Re: G1, G7 Ballistics Coeficient?
Order a copy of Bryan Litz's book "Applied Ballistics for Long Range Shooting":
http://www.appliedballisticsllc.com/index_files/Book.htm
It is an invaluable resource and Bryan does an excellent job of explaining external ballistics in layman's language.
Order a copy of Bryan Litz's book "Applied Ballistics for Long Range Shooting":
http://www.appliedballisticsllc.com/index_files/Book.htm
It is an invaluable resource and Bryan does an excellent job of explaining external ballistics in layman's language.
Re: G1, G7 Ballistics Coeficient?
oops, guess it really was a dumb question. thanks for the link treebasher
oops, guess it really was a dumb question. thanks for the link treebasher
Re: G1, G7 Ballistics Coeficient?
Here's a quick explanation:
http://02b0516.netsolhost.com/blog1/?p=62
Here's a quick explanation:
http://02b0516.netsolhost.com/blog1/?p=62
Re: G1, G7 Ballistics Coeficient?
its got to do with boolit profile......the older G1.......well them are the boolit profile of old....as in round nose...
the g7....think spitzer higher BC.......
its got to do with boolit profile......the older G1.......well them are the boolit profile of old....as in round nose...
the g7....think spitzer higher BC.......
Re: G1, G7 Ballistics Coeficient?
I think G1 is spitzer with flatbase
G5 is spitzer with boat tail
G7 is VLD profile
the BC is a comparison to bullets of these profiles being 1 inch in diameter and 1 pound in weight and there are more that this. The base of the profile is a BC of 1 and if you see a bc higher than 1 they aren't comparing the projectile to the correct profile like a high bc 50 cal bullet with a g1 bc higher than 1 is just a crutch or ball park and not the highest possible standard to compare it to
I think........
I think G1 is spitzer with flatbase
G5 is spitzer with boat tail
G7 is VLD profile
the BC is a comparison to bullets of these profiles being 1 inch in diameter and 1 pound in weight and there are more that this. The base of the profile is a BC of 1 and if you see a bc higher than 1 they aren't comparing the projectile to the correct profile like a high bc 50 cal bullet with a g1 bc higher than 1 is just a crutch or ball park and not the highest possible standard to compare it to
I think........
Re: G1, G7 Ballistics Coeficient?
We found one is not really better than the other, both give you roughly the same information and both require you to "tweak" the data to work.
However, you don't have to take my word for it, here is comparison conducted by someone else using Patagonia Loadbase 3 with real world Doppler, G1, & G7 as they compare to each other from 1000m to 1750, using the 338LM 250gr Scenar. This is raw data provided, neither the G1 or G7 numbers were adjusted to match, simply outputted as LB3 processes it.
We found similar results in comparing, including the use of Ballistics FTE, JBM, and BulletFlight -- at the end of the day, its so close it doesn't matter what you use. In our case Ballistics FTE G7 were much more optimistic than BulletFlight, leading to better results with BulletFlight. In both cases the G1 was closer in both elevation and windage. But your results may vary.
We found one is not really better than the other, both give you roughly the same information and both require you to "tweak" the data to work.
However, you don't have to take my word for it, here is comparison conducted by someone else using Patagonia Loadbase 3 with real world Doppler, G1, & G7 as they compare to each other from 1000m to 1750, using the 338LM 250gr Scenar. This is raw data provided, neither the G1 or G7 numbers were adjusted to match, simply outputted as LB3 processes it.
We found similar results in comparing, including the use of Ballistics FTE, JBM, and BulletFlight -- at the end of the day, its so close it doesn't matter what you use. In our case Ballistics FTE G7 were much more optimistic than BulletFlight, leading to better results with BulletFlight. In both cases the G1 was closer in both elevation and windage. But your results may vary.
Re: G1, G7 Ballistics Coeficient?
http://02b0516.netsolhost.com/blog1/?p=62
Berger Bulletin
June 17, 2009
A Better Ballistic Coefficient
For centuries now, science has been helping us gain a more accurate understanding of our world. The branch of science we care about as shooters is known as ballistics. The science of ballistics is well developed and understood by those who study it, but the tools and information being used by average shooters is not necessarily optimal for the shooter’s applications. In other words, there is a better, more accurate way for shooters to use ballistics to help them predict trajectories and hit targets. <span style="font-weight: bold">The purpose of this article is to present a better way for shooters to calculate ballistics.</span>
<span style="font-weight: bold">What is a Ballistic Coefficient?</span>
Most shooters, especially long range rifle shooters, are familiar with the Ballistic Coefficient (BC). Without getting into the math, I’ll define the ballistic coefficient in words as: <span style="font-weight: bold">The ability of the bullet to maintain velocity, in comparison to a ‘<span style="text-decoration: underline">standard projectile</span>’.</span> A high BC bullet can maintain velocity better than a low BC bullet under the same conditions. All measures of ballistic performance including drop and wind deflection are related to the bullet’s ability to maintain velocity. In short; the higher the BC, the better the all-around ballistic performance of the bullet will be.
<span style="font-weight: bold">How a Ballistic Coefficient is used</span>
Details of ballistic trajectories can be predicted with computer programs using all the relevant variables, including BC. As with all prediction programs; the accuracy of the outputs depends on the accuracy of the inputs. Here is where we have to examine the real meaning and implications of using a Ballistic Coefficient to characterize the bullet’s ability to maintain velocity.
It’s a relatively well known fact that the BC of a bullet is different at different velocities. Not many shooters know why it changes, or what the consequences are. To understand why a BC changes at different speeds, we have to go back to the definition of BC, which is: <span style="font-weight: bold">The ability of the bullet to maintain velocity, in comparison to a ‘<span style="text-decoration: underline">standard projectile</span>’.</span> It’s the ‘standard projectile’ part of the definition that we need to key in on. What is the ‘standard projectile’? What does it look like?
To date, the ‘standard projectile’ used to define BCs for the entire sporting arms industry is the G1 standard projectile. The G1 standard projectile which is shown in Figure 1 has a short nose, flat base, and bears more resemblance to a pistol bullet or an old unjacketed lead black powder cartridge rifle bullet than to a modern long range rifle bullet.
<span style="font-weight: bold">The reason why the BC of a modern long range bullet changes so much at different velocities is because modern bullets are so different in shape compared to the G1 standard that its BC is based on.</span> In other words, the drag of a modern long range bullet changes differently than the G1 standard projectile, so the coefficient relating the two (the ballistic coefficient) has to change with velocity.
There are several ways to manage the problems caused by the dependence of BC on velocity. One way is to use a G1 BC that’s averaged for the speed range you’re interested in. This will get you close, but what if the BC of the bullet is advertised for a speed range that’s different than what you’re interested in? It’s not easy to adjust the BC for different average velocities. Another way to deal with the problem of a velocity dependant BC is to give the BC in several velocity ‘bands’ (Sierra bullets uses this approach to advertise the BCs of their bullets). This can be an accurate approach, but it leaves a lot of room for misinterpretation. For example, many shooters don’t understand why there are different BCs and choose the wrong one. Furthermore, not all ballistics programs allow you to input multiple BCs. In short; <span style="font-weight: bold">the use of the non-representative G1 standard (Figure 1) to define BC is responsible for the velocity dependence and associated problems with BCs.</span>
<span style="font-weight: bold">A better standard for long range bullets</span>
If you look at the G1 standard projectile again in Figure 1, you might think; “it’s too bad there isn’t a standard that’s more representative for modern long range bullets”. In fact, there are several standard projectiles, all with different shapes, that are much more representative of modern long range bullets than the G1 standard. The standard that bears the closest resemblance to most modern long range bullets is the G7 standard, shown in Figure 2.
As you can see, the G7 standard projectile, with its long boat tail and pointed ogive bears a much stronger resemblance to a modern long range bullet than the G1 standard projectile. As a result, <span style="font-weight: bold">the BC of a modern long range bullet that’s referenced to the G7 standard is constant for all velocities!</span> In other words, a trajectory that’s calculated with a ‘G7 BC’ doesn’t suffer from the same velocity dependence problems and inaccuracies as calculations that are made with a G1 BC.
Another benefit of using G7 BC’s is that it allows a more fair comparison between bullets. For example, consider two .30 caliber 168 grain match bullets from different manufacturers. Even if both projectiles are identical in shape and weight, it’s possible for them to have different advertised BCs if the BCs are calculated for different velocities. For instance, if one of the bullet’s BC is calculated for a 3000 fps (muzzle velocity) and the other is calculated for an average velocity between 3000 fps and 1500 fps, then the BC that’s based only on muzzle velocity will be higher, but less relevant for long range shooting than the average BC. In other words, the two bullets actually have the same BC, but the ‘smoke and mirrors’ that results from the velocity dependence of G1 BC creates the illusion that one bullet is better than the other. If you considered the G7 BC of the two bullets, it would be the same for all speeds.
You may observe that not all bullets look more like the G7 standard, and that’s true. For the short, flat based, blunt nosed bullets, the G1 standard is actually more representative. For that reason, BCs for flat based bullets should continue to be referenced to the G1 standard. In other words, <span style="font-weight: bold">the G7 BC is better for boat tailed bullets, while G1 BCs are better for flat based bullets.</span>
<span style="font-weight: bold">Why were we stuck with G1 for so long?</span>
One obvious difference between G1 BCs and G7 BCs is that the numeric value of the G7 BC is lower than the numeric value of the G1 BC. For example, if a bullet has a G1 BC of .550, the G7 BC will be close to .282 (same bullet). Even though the G7 BC of .282 is a much more accurate representation of the bullet at all speeds, <span style="font-weight: bold">the numeric value of the G7 BC is lower</span>. If you know anything about marketing, then it’s obvious why we’ve been stuck with G1 BCs for so long. <span style="font-weight: bold">Since the G1 standard projectile is the highest drag standard, BCs referenced to that standard will be higher than BCs referenced to any other standard.</span> As we know, when it comes to marketing, the facts and quality of information is often compromised in order to present a more favorable advertisement. For many years, bullet makers have known(<span style="font-weight: bold">*</span>) that the G1 standard is a poor standard for long range bullets but continue to use it. Why? One reason is because it’s believed that the first company to advertise G7 BCs will ‘confuse’ people, and the lower numeric value of the G7 BC will push people away from their product.
It’s easy to understand the fear of being the first to do something new. It will take time to explain and it may hurt sales at first. That’s OK. At Berger Bullets we are committed to the success of shooters. Mostly that means making the best bullets possible. That commitment also includes providing shooters with the most suitable and accurate information so they can use those bullets most effectively. Berger’s commitment to the shooter is why we are making the leap to G7 referenced BCs. The change will take time to get used to, but in the end, shooters will be empowered to make better informed decisions about their equipment. In the end, shooters will be able to calculate more accurate trajectories. In the end, the other bullet companies will follow and provide G7 BCs for their long range bullets because it’s the right thing to do. <span style="font-weight: bold">In the end, this change will mean greater success for shooters.</span>
(<span style="font-weight: bold">*</span>-Sierra bullets wrote an article which acknowledges that G7 referenced BCs are more appropriate for modern long range bullets: http://www.exteriorballistics.com/ebexplained/articles/the_ballistic_coefficient.pdf )
<span style="font-weight: bold">Using the G7 BC: Calculating trajectories</span>
Most modern ballistics programs are being created with the ability to use BCs that are referenced to different standards (G1, G5, G7, etc). Calculating a trajectory with a G7 BC is as simple as selecting “G7 BC” in the program, and giving the program a G7 BC instead of a G1 BC. All the other inputs are handled the same. There are many free ballistics programs that can calculate trajectories using G7 BCs including the well known free online calculator from JBM (http://www.eskimo.com/~jbm/cgi-bin/jbmtraj-5.0.cgi). The JBM program is extremely accurate when given accurate inputs. JBM’s page also has links to free ballistics programs that can be downloaded and run on your computer when not connected to the internet. One program that’s free for download and has the ability to use G7 BCs is AlBal (http://www.eskimo.com/~jbm/software/software.html).
<span style="font-weight: bold">Using the G7 BC: Comparing bullets</span>
One way that BC is used by shooters is to compare the relative performance of bullets. Comparing bullets by BC is only possible if the BCs are referenced to the same standard. For example, if you know the G1 BC of one bullet is .500, and the G7 BC for another bullet is .230, it’s impossible to tell which is better just from the BCs. Since other bullet companies don’t yet advertise G7 BCs for their bullets, how is it possible to compare other brands bullets to Berger’s G7 BC? Ideally, one tester would test the bullets from all the companies using the same method, and report the G7 BCs. I have recently completed such a study and the test results including G7 BC’s for over 175 bullets of all major brands are published in one book. The book is called: Applied Ballistics for Long Range Shooting and is available from Applied Ballistics, LLC (http://www.appliedballisticsllc.com/index_files/Book.htm). I began the testing and writing of this book 2 years before I became the Chief Ballistician for Berger Bullets. I used the same test procedure (repeatable within +/- 1%) to measure the G1 and G7 BCs for all brands of bullets so meaningful comparisons can be made between brands.
<span style="font-weight: bold">Conclusion</span>
Science has a good track record as a method for reaching accurate conclusions. Ballistics is the science of shooting, and the use of the G1 standard has been a glaring error in the way that we shooters apply our science. For too long now, the unfortunate influences of marketing and advertising have kept us from being able to use our science to its fullest potential. As part of our commitment to the success of shooters, Berger Bullets is bringing the application of small arms ballistics out of the marketing hype and G1 dark ages and offering accurate and properly referenced G7 BCs for our long range bullets.
All of the pieces are now in place for shooters to take full advantage of this more accurate kind of BC. Berger now provides G7 BCs for our bullets. The book: Applied Ballistics for Long Range Shooting provides G7 BCs for all other brands of bullets. Ballistics programs are available that can calculate trajectories using the G7 BCs. In conclusion; everything is now available for shooters to take immediate advantage of this new type of BC and do everything that was possible with the old G1 BCs, only better.
Bryan Litz
Ballistician
http://02b0516.netsolhost.com/blog1/?p=62
Berger Bulletin
June 17, 2009
A Better Ballistic Coefficient
For centuries now, science has been helping us gain a more accurate understanding of our world. The branch of science we care about as shooters is known as ballistics. The science of ballistics is well developed and understood by those who study it, but the tools and information being used by average shooters is not necessarily optimal for the shooter’s applications. In other words, there is a better, more accurate way for shooters to use ballistics to help them predict trajectories and hit targets. <span style="font-weight: bold">The purpose of this article is to present a better way for shooters to calculate ballistics.</span>
<span style="font-weight: bold">What is a Ballistic Coefficient?</span>
Most shooters, especially long range rifle shooters, are familiar with the Ballistic Coefficient (BC). Without getting into the math, I’ll define the ballistic coefficient in words as: <span style="font-weight: bold">The ability of the bullet to maintain velocity, in comparison to a ‘<span style="text-decoration: underline">standard projectile</span>’.</span> A high BC bullet can maintain velocity better than a low BC bullet under the same conditions. All measures of ballistic performance including drop and wind deflection are related to the bullet’s ability to maintain velocity. In short; the higher the BC, the better the all-around ballistic performance of the bullet will be.
<span style="font-weight: bold">How a Ballistic Coefficient is used</span>
Details of ballistic trajectories can be predicted with computer programs using all the relevant variables, including BC. As with all prediction programs; the accuracy of the outputs depends on the accuracy of the inputs. Here is where we have to examine the real meaning and implications of using a Ballistic Coefficient to characterize the bullet’s ability to maintain velocity.
It’s a relatively well known fact that the BC of a bullet is different at different velocities. Not many shooters know why it changes, or what the consequences are. To understand why a BC changes at different speeds, we have to go back to the definition of BC, which is: <span style="font-weight: bold">The ability of the bullet to maintain velocity, in comparison to a ‘<span style="text-decoration: underline">standard projectile</span>’.</span> It’s the ‘standard projectile’ part of the definition that we need to key in on. What is the ‘standard projectile’? What does it look like?
To date, the ‘standard projectile’ used to define BCs for the entire sporting arms industry is the G1 standard projectile. The G1 standard projectile which is shown in Figure 1 has a short nose, flat base, and bears more resemblance to a pistol bullet or an old unjacketed lead black powder cartridge rifle bullet than to a modern long range rifle bullet.
<span style="font-weight: bold">The reason why the BC of a modern long range bullet changes so much at different velocities is because modern bullets are so different in shape compared to the G1 standard that its BC is based on.</span> In other words, the drag of a modern long range bullet changes differently than the G1 standard projectile, so the coefficient relating the two (the ballistic coefficient) has to change with velocity.
There are several ways to manage the problems caused by the dependence of BC on velocity. One way is to use a G1 BC that’s averaged for the speed range you’re interested in. This will get you close, but what if the BC of the bullet is advertised for a speed range that’s different than what you’re interested in? It’s not easy to adjust the BC for different average velocities. Another way to deal with the problem of a velocity dependant BC is to give the BC in several velocity ‘bands’ (Sierra bullets uses this approach to advertise the BCs of their bullets). This can be an accurate approach, but it leaves a lot of room for misinterpretation. For example, many shooters don’t understand why there are different BCs and choose the wrong one. Furthermore, not all ballistics programs allow you to input multiple BCs. In short; <span style="font-weight: bold">the use of the non-representative G1 standard (Figure 1) to define BC is responsible for the velocity dependence and associated problems with BCs.</span>
<span style="font-weight: bold">A better standard for long range bullets</span>
If you look at the G1 standard projectile again in Figure 1, you might think; “it’s too bad there isn’t a standard that’s more representative for modern long range bullets”. In fact, there are several standard projectiles, all with different shapes, that are much more representative of modern long range bullets than the G1 standard. The standard that bears the closest resemblance to most modern long range bullets is the G7 standard, shown in Figure 2.
As you can see, the G7 standard projectile, with its long boat tail and pointed ogive bears a much stronger resemblance to a modern long range bullet than the G1 standard projectile. As a result, <span style="font-weight: bold">the BC of a modern long range bullet that’s referenced to the G7 standard is constant for all velocities!</span> In other words, a trajectory that’s calculated with a ‘G7 BC’ doesn’t suffer from the same velocity dependence problems and inaccuracies as calculations that are made with a G1 BC.
Another benefit of using G7 BC’s is that it allows a more fair comparison between bullets. For example, consider two .30 caliber 168 grain match bullets from different manufacturers. Even if both projectiles are identical in shape and weight, it’s possible for them to have different advertised BCs if the BCs are calculated for different velocities. For instance, if one of the bullet’s BC is calculated for a 3000 fps (muzzle velocity) and the other is calculated for an average velocity between 3000 fps and 1500 fps, then the BC that’s based only on muzzle velocity will be higher, but less relevant for long range shooting than the average BC. In other words, the two bullets actually have the same BC, but the ‘smoke and mirrors’ that results from the velocity dependence of G1 BC creates the illusion that one bullet is better than the other. If you considered the G7 BC of the two bullets, it would be the same for all speeds.
You may observe that not all bullets look more like the G7 standard, and that’s true. For the short, flat based, blunt nosed bullets, the G1 standard is actually more representative. For that reason, BCs for flat based bullets should continue to be referenced to the G1 standard. In other words, <span style="font-weight: bold">the G7 BC is better for boat tailed bullets, while G1 BCs are better for flat based bullets.</span>
<span style="font-weight: bold">Why were we stuck with G1 for so long?</span>
One obvious difference between G1 BCs and G7 BCs is that the numeric value of the G7 BC is lower than the numeric value of the G1 BC. For example, if a bullet has a G1 BC of .550, the G7 BC will be close to .282 (same bullet). Even though the G7 BC of .282 is a much more accurate representation of the bullet at all speeds, <span style="font-weight: bold">the numeric value of the G7 BC is lower</span>. If you know anything about marketing, then it’s obvious why we’ve been stuck with G1 BCs for so long. <span style="font-weight: bold">Since the G1 standard projectile is the highest drag standard, BCs referenced to that standard will be higher than BCs referenced to any other standard.</span> As we know, when it comes to marketing, the facts and quality of information is often compromised in order to present a more favorable advertisement. For many years, bullet makers have known(<span style="font-weight: bold">*</span>) that the G1 standard is a poor standard for long range bullets but continue to use it. Why? One reason is because it’s believed that the first company to advertise G7 BCs will ‘confuse’ people, and the lower numeric value of the G7 BC will push people away from their product.
It’s easy to understand the fear of being the first to do something new. It will take time to explain and it may hurt sales at first. That’s OK. At Berger Bullets we are committed to the success of shooters. Mostly that means making the best bullets possible. That commitment also includes providing shooters with the most suitable and accurate information so they can use those bullets most effectively. Berger’s commitment to the shooter is why we are making the leap to G7 referenced BCs. The change will take time to get used to, but in the end, shooters will be empowered to make better informed decisions about their equipment. In the end, shooters will be able to calculate more accurate trajectories. In the end, the other bullet companies will follow and provide G7 BCs for their long range bullets because it’s the right thing to do. <span style="font-weight: bold">In the end, this change will mean greater success for shooters.</span>
(<span style="font-weight: bold">*</span>-Sierra bullets wrote an article which acknowledges that G7 referenced BCs are more appropriate for modern long range bullets: http://www.exteriorballistics.com/ebexplained/articles/the_ballistic_coefficient.pdf )
<span style="font-weight: bold">Using the G7 BC: Calculating trajectories</span>
Most modern ballistics programs are being created with the ability to use BCs that are referenced to different standards (G1, G5, G7, etc). Calculating a trajectory with a G7 BC is as simple as selecting “G7 BC” in the program, and giving the program a G7 BC instead of a G1 BC. All the other inputs are handled the same. There are many free ballistics programs that can calculate trajectories using G7 BCs including the well known free online calculator from JBM (http://www.eskimo.com/~jbm/cgi-bin/jbmtraj-5.0.cgi). The JBM program is extremely accurate when given accurate inputs. JBM’s page also has links to free ballistics programs that can be downloaded and run on your computer when not connected to the internet. One program that’s free for download and has the ability to use G7 BCs is AlBal (http://www.eskimo.com/~jbm/software/software.html).
<span style="font-weight: bold">Using the G7 BC: Comparing bullets</span>
One way that BC is used by shooters is to compare the relative performance of bullets. Comparing bullets by BC is only possible if the BCs are referenced to the same standard. For example, if you know the G1 BC of one bullet is .500, and the G7 BC for another bullet is .230, it’s impossible to tell which is better just from the BCs. Since other bullet companies don’t yet advertise G7 BCs for their bullets, how is it possible to compare other brands bullets to Berger’s G7 BC? Ideally, one tester would test the bullets from all the companies using the same method, and report the G7 BCs. I have recently completed such a study and the test results including G7 BC’s for over 175 bullets of all major brands are published in one book. The book is called: Applied Ballistics for Long Range Shooting and is available from Applied Ballistics, LLC (http://www.appliedballisticsllc.com/index_files/Book.htm). I began the testing and writing of this book 2 years before I became the Chief Ballistician for Berger Bullets. I used the same test procedure (repeatable within +/- 1%) to measure the G1 and G7 BCs for all brands of bullets so meaningful comparisons can be made between brands.
<span style="font-weight: bold">Conclusion</span>
Science has a good track record as a method for reaching accurate conclusions. Ballistics is the science of shooting, and the use of the G1 standard has been a glaring error in the way that we shooters apply our science. For too long now, the unfortunate influences of marketing and advertising have kept us from being able to use our science to its fullest potential. As part of our commitment to the success of shooters, Berger Bullets is bringing the application of small arms ballistics out of the marketing hype and G1 dark ages and offering accurate and properly referenced G7 BCs for our long range bullets.
All of the pieces are now in place for shooters to take full advantage of this more accurate kind of BC. Berger now provides G7 BCs for our bullets. The book: Applied Ballistics for Long Range Shooting provides G7 BCs for all other brands of bullets. Ballistics programs are available that can calculate trajectories using the G7 BCs. In conclusion; everything is now available for shooters to take immediate advantage of this new type of BC and do everything that was possible with the old G1 BCs, only better.
Bryan Litz
Ballistician
Re: G1, G7 Ballistics Coeficient?
Quoting things is easy, but that doesn't make it magic...
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">A central subject of the book is the proposed use of the G7 drag model
instead of the usual and widely available G1 function. While the general use
of G7 (first published in 1958) can be debated, since it's not a good match
for other bullets designs, but the more streamlined, "VLD" types. it's
nevertheless a good case in point.
Whereas it's clear that the G7 drag function matches more closely the usual
low-drag designs used in long range shooting/hunting than the G1 (something
that's expressed in my website since its beginning) I fall short to notice
why Mr. Litz says that the velocity-dependence of G1 is a "problem", when
the same dependence is there with G7 or any other "G" function, because
that's simply unavoidable.
In my estimation that's perplexing, since that's the very reason for having
a number of "G" functions and not an argument in itself when debating the
merits of G7 as a better function to match the current designs, something
that was clear for the last fifty years.
Both G1 and G7 will respond in the same manner, yielding the same amount of
error in drop predictions, given the same variation of, for example, muzzle
velocity. And as expected, both will show the same "resilience" to
uncertainty in their determination.
It's significant to realize, in order to dissipate any confusion, that the
method used to compute a trajectory based on a G7 value is the same as the
one with a G1 value. Just different drag models. Then make your selection to
run Siacci/Mayevski, PM, MPM, etc.
Try out making a run using a G7 BC and the output will come close (sub-MOA
up to 1500 yards) to another run made by using a well-defined G1 BC (as
studied by McCoy, Weinacht, Cooper, Newill). An interested reader can verify
that by relying on the data supplied by the book and the accompanying
software (which is not a Siacci-based model, thus requiring a near-constant
BC along the entire range).</div></div>
Although the bold additions were a nice touch ...
Quoting things is easy, but that doesn't make it magic...
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">A central subject of the book is the proposed use of the G7 drag model
instead of the usual and widely available G1 function. While the general use
of G7 (first published in 1958) can be debated, since it's not a good match
for other bullets designs, but the more streamlined, "VLD" types. it's
nevertheless a good case in point.
Whereas it's clear that the G7 drag function matches more closely the usual
low-drag designs used in long range shooting/hunting than the G1 (something
that's expressed in my website since its beginning) I fall short to notice
why Mr. Litz says that the velocity-dependence of G1 is a "problem", when
the same dependence is there with G7 or any other "G" function, because
that's simply unavoidable.
In my estimation that's perplexing, since that's the very reason for having
a number of "G" functions and not an argument in itself when debating the
merits of G7 as a better function to match the current designs, something
that was clear for the last fifty years.
Both G1 and G7 will respond in the same manner, yielding the same amount of
error in drop predictions, given the same variation of, for example, muzzle
velocity. And as expected, both will show the same "resilience" to
uncertainty in their determination.
It's significant to realize, in order to dissipate any confusion, that the
method used to compute a trajectory based on a G7 value is the same as the
one with a G1 value. Just different drag models. Then make your selection to
run Siacci/Mayevski, PM, MPM, etc.
Try out making a run using a G7 BC and the output will come close (sub-MOA
up to 1500 yards) to another run made by using a well-defined G1 BC (as
studied by McCoy, Weinacht, Cooper, Newill). An interested reader can verify
that by relying on the data supplied by the book and the accompanying
software (which is not a Siacci-based model, thus requiring a near-constant
BC along the entire range).</div></div>
Although the bold additions were a nice touch ...
Re: G1, G7 Ballistics Coeficient?
Found this cool HTML to UBB converter...
http://www.seabreezecomputers.com/html2bbcode/
Found this cool HTML to UBB converter...
http://www.seabreezecomputers.com/html2bbcode/
Re: G1, G7 Ballistics Coeficient?
Frank,
I'll forward all my ballistics questions to you from now on. You're clearly the wizard. You and the un-named source of that quote.
-Bryan
Frank,
I'll forward all my ballistics questions to you from now on. You're clearly the wizard. You and the un-named source of that quote.
-Bryan
Re: G1, G7 Ballistics Coeficient?
Bryan,
I am in no way a wizard, however you are not the only source in the world for ballistic information ... and my own testing shows, tweaking is every bit as necessary.
You know the source, you have spoke to him... it's not a secret, if you want his information I will give it too you.
What we have done we recorded, videotaped and the information is there for all to see, and the G7 was just a muzzle velocity dependent as well as just as off as anything else .. in this case the G1 was more accurate, although in BulletFlight the G7 was better than the G7 in Ballistics.
Sorry I don't blindly follow, but have a bit of curiosity myself and actually test things against each other. I shoot and record, it's my curiosity that helps move things forward.
So I take it you disagree with not only the assessment in the quote but also the data as compared to the Doppler information I posted ?
Bryan,
I am in no way a wizard, however you are not the only source in the world for ballistic information ... and my own testing shows, tweaking is every bit as necessary.
You know the source, you have spoke to him... it's not a secret, if you want his information I will give it too you.
What we have done we recorded, videotaped and the information is there for all to see, and the G7 was just a muzzle velocity dependent as well as just as off as anything else .. in this case the G1 was more accurate, although in BulletFlight the G7 was better than the G7 in Ballistics.
Sorry I don't blindly follow, but have a bit of curiosity myself and actually test things against each other. I shoot and record, it's my curiosity that helps move things forward.
So I take it you disagree with not only the assessment in the quote but also the data as compared to the Doppler information I posted ?
Re: G1, G7 Ballistics Coeficient?
I'll go with what Bryan says. G7 is where it is with all the ballistic calculators I use and I judge them against results on paper to 1000 yards with a .308. I shoot Berger 185 BTLR Bullets and his info is dead on everytime. Why should I look at something else? I've been down the 175 SMK road at 1000 yards using a G1 BC before and it just doesn't work as well. I shoot F Class competitively.
The key to calculating accurate information is by entering accurate weather conditions to start with. I suspect most don't know the difference between pressure altitude and density altitude let alone know how it affects bullet flight.
I suggest some of you folks read Applied Ballistics that Bryan wrote for a deeper understanding of the subject. There is way too much heresay on the internet and much of it is not accurate and only a rehash of someone's opinion.
I'll go with what Bryan says. G7 is where it is with all the ballistic calculators I use and I judge them against results on paper to 1000 yards with a .308. I shoot Berger 185 BTLR Bullets and his info is dead on everytime. Why should I look at something else? I've been down the 175 SMK road at 1000 yards using a G1 BC before and it just doesn't work as well. I shoot F Class competitively.
The key to calculating accurate information is by entering accurate weather conditions to start with. I suspect most don't know the difference between pressure altitude and density altitude let alone know how it affects bullet flight.
I suggest some of you folks read Applied Ballistics that Bryan wrote for a deeper understanding of the subject. There is way too much heresay on the internet and much of it is not accurate and only a rehash of someone's opinion.
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Leaddog</div><div class="ubbcode-body">I'll go with what Bryan says. G7 is where it is with all the ballistic calculators I use and I judge them against results on paper to 1000 yards with a .308. I shoot Berger 185 BTLR Bullets and his info is dead on everytime. Why should I look at something else? I've been down the 175 SMK road at 1000 yards using a G1 BC before and it just doesn't work as well. I shoot F Class competitively.
The key to calculating accurate information is by entering accurate weather conditions to start with. I suspect most don't know the difference between pressure altitude and density altitude let alone know how it affects bullet flight.
I suggest some of you folks read Applied Ballistics that Bryan wrote for a deeper understanding of the subject. There is way too much heresay on the internet and much of it is not accurate and only a rehash of someone's opinion.</div></div>
Please spare me,
Like this is hearsay...
And for your information we did our own testing and recorded everything (read videotaped) from Chronographing to Kestrel, to inputing data and results... call it hearsay all you want but facts are facts...
telling me I don't know how atmospheric conditions work, or the difference between DA and Barometric pressure... seriously ?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Leaddog</div><div class="ubbcode-body">I'll go with what Bryan says. G7 is where it is with all the ballistic calculators I use and I judge them against results on paper to 1000 yards with a .308. I shoot Berger 185 BTLR Bullets and his info is dead on everytime. Why should I look at something else? I've been down the 175 SMK road at 1000 yards using a G1 BC before and it just doesn't work as well. I shoot F Class competitively.
The key to calculating accurate information is by entering accurate weather conditions to start with. I suspect most don't know the difference between pressure altitude and density altitude let alone know how it affects bullet flight.
I suggest some of you folks read Applied Ballistics that Bryan wrote for a deeper understanding of the subject. There is way too much heresay on the internet and much of it is not accurate and only a rehash of someone's opinion.</div></div>
Please spare me,
Like this is hearsay...
And for your information we did our own testing and recorded everything (read videotaped) from Chronographing to Kestrel, to inputing data and results... call it hearsay all you want but facts are facts...
telling me I don't know how atmospheric conditions work, or the difference between DA and Barometric pressure... seriously ?
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Leaddog</div><div class="ubbcode-body">I'll go with what Bryan says. G7 is where it is with all the ballistic calculators I use and I judge them against results on paper to 1000 yards with a .308. I shoot Berger 185 BTLR Bullets and his info is dead on everytime. Why should I look at something else? I've been down the 175 SMK road at 1000 yards using a G1 BC before and it just doesn't work as well. I shoot F Class competitively.
The key to calculating accurate information is by entering accurate weather conditions to start with. I suspect most don't know the difference between pressure altitude and density altitude let alone know how it affects bullet flight.
I suggest some of you folks read Applied Ballistics that Bryan wrote for a deeper understanding of the subject. There is way too much heresay on the internet and much of it is not accurate and only a rehash of someone's opinion.</div></div>
Please spare me,
Like this is hearsay...
And for your information we did our own testing and recorded everything (read videotaped) from Chronographing to Kestrel, to inputing data and results... call it hearsay all you want but facts are facts...
telling me I don't know how atmospheric conditions work, or the difference between DA and Barometric pressure... seriously ?
</div></div>
Pressure altitude and barometric pressure are not the same thing when current conditions are other than 29.92 or 29.53 or whatever standard you use. Would you like to know the difference?
Much of this 'tweaking error' you speak of comes from loads that are not consistent (high SD's) and/or velocities recorded on equipment less than truly accurate.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Leaddog</div><div class="ubbcode-body">I'll go with what Bryan says. G7 is where it is with all the ballistic calculators I use and I judge them against results on paper to 1000 yards with a .308. I shoot Berger 185 BTLR Bullets and his info is dead on everytime. Why should I look at something else? I've been down the 175 SMK road at 1000 yards using a G1 BC before and it just doesn't work as well. I shoot F Class competitively.
The key to calculating accurate information is by entering accurate weather conditions to start with. I suspect most don't know the difference between pressure altitude and density altitude let alone know how it affects bullet flight.
I suggest some of you folks read Applied Ballistics that Bryan wrote for a deeper understanding of the subject. There is way too much heresay on the internet and much of it is not accurate and only a rehash of someone's opinion.</div></div>
Please spare me,
Like this is hearsay...
And for your information we did our own testing and recorded everything (read videotaped) from Chronographing to Kestrel, to inputing data and results... call it hearsay all you want but facts are facts...
telling me I don't know how atmospheric conditions work, or the difference between DA and Barometric pressure... seriously ?
</div></div>
Pressure altitude and barometric pressure are not the same thing when current conditions are other than 29.92 or 29.53 or whatever standard you use. Would you like to know the difference?
Much of this 'tweaking error' you speak of comes from loads that are not consistent (high SD's) and/or velocities recorded on equipment less than truly accurate.
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Bryan,
I am in no way a wizard, however you are not the only source in the world for ballistic information ... and my own testing shows, tweaking is every bit as necessary.
You know the source, you have spoke to him... it's not a secret, if you want his information I will give it too you.
What we have done we recorded, videotaped and the information is there for all to see, and the G7 was just a muzzle velocity dependent as well as just as off as anything else .. in this case the G1 was more accurate, although in BulletFlight the G7 was better than the G7 in Ballistics.
Sorry I don't blindly follow, but have a bit of curiosity myself and actually test things against each other. I shoot and record, it's my curiosity that helps move things forward.
So I take it you disagree with not only the assessment in the quote but also the data as compared to the Doppler information I posted ? </div></div>
OK, I know who you're talking about now. I consider Gus a good friend, but we do disagree on the proper way to solve the equations of projectile motion. Gus is using Pejsa's equations (or some variant of them), which do not interpret BC the same as conventional programs. That's why LB3 produces 'different' results compared to a normal program. The G1 predictions in LB3 are better than G1 predictions in other programs. That's because the G1 'curve' in Pejsa's equations can be shaped however you want. Of course it's smart to make the curve look more like a G7, so it's no surprise that the G1 and G7 solutions in LB3 are similar.
When you're dealing with the equations of motion and BC's <span style="font-style: italic">the way they're intended</span>, the G7 standard produces more accurate trajectory predictions. Look at the standard projectiles and tell me you believe otherwise.
When you said:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">What we have done we recorded, videotaped and the information is there for all to see, and the G7 was just a muzzle velocity dependent as well as just as off as anything else ..</div></div>
Did you mean that the accuracy of both the G7 and G1 solution depends on knowing the right MV? I'll give you that one. You do need to know inputs accurately no matter what standard you use.
I know that I'm not the only source in the world for ballistics and it's good that people don't think that. However I challenge you to find another credible source to advocate G1 over G7 for trajectory modeling of long range bullets.
Yes, both G1 and G7 BC's change with velocity. But G7's change MUCH MUCH less (unless you're using LB3 which makes the G1 curve look like a G7 curve) and that's why they're better.
-Bryan
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Bryan,
I am in no way a wizard, however you are not the only source in the world for ballistic information ... and my own testing shows, tweaking is every bit as necessary.
You know the source, you have spoke to him... it's not a secret, if you want his information I will give it too you.
What we have done we recorded, videotaped and the information is there for all to see, and the G7 was just a muzzle velocity dependent as well as just as off as anything else .. in this case the G1 was more accurate, although in BulletFlight the G7 was better than the G7 in Ballistics.
Sorry I don't blindly follow, but have a bit of curiosity myself and actually test things against each other. I shoot and record, it's my curiosity that helps move things forward.
So I take it you disagree with not only the assessment in the quote but also the data as compared to the Doppler information I posted ? </div></div>
OK, I know who you're talking about now. I consider Gus a good friend, but we do disagree on the proper way to solve the equations of projectile motion. Gus is using Pejsa's equations (or some variant of them), which do not interpret BC the same as conventional programs. That's why LB3 produces 'different' results compared to a normal program. The G1 predictions in LB3 are better than G1 predictions in other programs. That's because the G1 'curve' in Pejsa's equations can be shaped however you want. Of course it's smart to make the curve look more like a G7, so it's no surprise that the G1 and G7 solutions in LB3 are similar.
When you're dealing with the equations of motion and BC's <span style="font-style: italic">the way they're intended</span>, the G7 standard produces more accurate trajectory predictions. Look at the standard projectiles and tell me you believe otherwise.
When you said:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">What we have done we recorded, videotaped and the information is there for all to see, and the G7 was just a muzzle velocity dependent as well as just as off as anything else ..</div></div>
Did you mean that the accuracy of both the G7 and G1 solution depends on knowing the right MV? I'll give you that one. You do need to know inputs accurately no matter what standard you use.
I know that I'm not the only source in the world for ballistics and it's good that people don't think that. However I challenge you to find another credible source to advocate G1 over G7 for trajectory modeling of long range bullets.
Yes, both G1 and G7 BC's change with velocity. But G7's change MUCH MUCH less (unless you're using LB3 which makes the G1 curve look like a G7 curve) and that's why they're better.
-Bryan
Re: G1, G7 Ballistics Coeficient?
So, why do these program allow and help you run the actual numbers... and tweak the G7...we found the proper G7 to be .237, seem odd for something not subject to muzzle velocity variations.
we didn't use standard pressure it was inputted and calculated in real time. We went straight from chronograph to 1000 yards with it, using more than one rifle. Our Kestrels were dead nuts on.
What do you think I was using a stock Remington, how about a custom GAP... Bartlein barrel with less than 1500 rounds down the tube. MV 2770fps SD was less than 10...
As I said we recorded everything
Maybe you have no idea how to work a program if you can't get the G1 to work, not to mention the above data was from Lapua test, I doubt they compared with Doppler and didn't know how to input the data... clearly the data posted speaks for itself, it was raw data...unadjusted.
Let me guess, you shot F Class and know Bryan so you rule the world, nobody knows how to do this but you. Cause I have no clue and information I have comes from someone other than Bryan so it has to be wrong.
Fuck, in F Class you get sighters, if you can't hit a 6X6 target board and get on target I don't what you know. Any fool can run JBM and get on paper even at 1000 yards, G1 or anything else, Telling me you didn't use any sighters prior to score.
So, why do these program allow and help you run the actual numbers... and tweak the G7...we found the proper G7 to be .237, seem odd for something not subject to muzzle velocity variations.
we didn't use standard pressure it was inputted and calculated in real time. We went straight from chronograph to 1000 yards with it, using more than one rifle. Our Kestrels were dead nuts on.
What do you think I was using a stock Remington, how about a custom GAP... Bartlein barrel with less than 1500 rounds down the tube. MV 2770fps SD was less than 10...
As I said we recorded everything
Maybe you have no idea how to work a program if you can't get the G1 to work, not to mention the above data was from Lapua test, I doubt they compared with Doppler and didn't know how to input the data... clearly the data posted speaks for itself, it was raw data...unadjusted.
Let me guess, you shot F Class and know Bryan so you rule the world, nobody knows how to do this but you. Cause I have no clue and information I have comes from someone other than Bryan so it has to be wrong.
Fuck, in F Class you get sighters, if you can't hit a 6X6 target board and get on target I don't what you know. Any fool can run JBM and get on paper even at 1000 yards, G1 or anything else, Telling me you didn't use any sighters prior to score.
Re: G1, G7 Ballistics Coeficient?
Bryan,
Not advocating one over the other, just saying there is no magic to G7, it still needs tweaking to a degree. And is MV dependent, like anything else.
Clearly the way Ballistics FTE processes it, and Bulletflight for example, because the two offer two different answers to the same questions. That tells you something, or at least tells me something. Adjusting the G7 to .237 helps, in Bulletflight it was adjusted to .243... same values, different answers.
But what the fuck do I know, I'm just an idiot with a website, maybe I need to get George to build me an F Class gun so I can get some credibility.
Bryan,
Not advocating one over the other, just saying there is no magic to G7, it still needs tweaking to a degree. And is MV dependent, like anything else.
Clearly the way Ballistics FTE processes it, and Bulletflight for example, because the two offer two different answers to the same questions. That tells you something, or at least tells me something. Adjusting the G7 to .237 helps, in Bulletflight it was adjusted to .243... same values, different answers.
But what the fuck do I know, I'm just an idiot with a website, maybe I need to get George to build me an F Class gun so I can get some credibility.
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">So, why do these program allow and help you run the actual numbers... and tweak the G7...we found the proper G7 to be .237, seem odd for something not subject to muzzle velocity variations.
we didn't use standard pressure it was inputted and calculated in real time. We went straight from chronograph to 1000 yards with it, using more than one rifle. Our Kestrels were dead nuts on.
What do you think I was using a stock Remington, how about a custom GAP... Bartlein barrel with less than 1500 rounds down the tube. MV 2770fps SD was less than 10...
As I said we recorded everything
Maybe you have no idea how to work a program if you can't get the G1 to work, not to mention the above data was from Lapua test, I doubt they compared with Doppler and didn't know how to input the data... clearly the data posted speaks for itself, it was raw data...unadjusted.
Let me guess, you shot F Class and know Bryan so you rule the world, nobody knows how to do this but you. Cause I have no clue and information I have comes from someone other than Bryan so it has to be wrong.
Fuck, in F Class you get sighters, if you can't hit a 6X6 target board and get on target I don't what you know. Any fool can run JBM and get on paper even at 1000 yards, G1 or anything else, Telling me you didn't use any sighters prior to score. </div></div>
I tried to have a civil conversation with you but I see that isn't working. You brought up a few good points, Bryan did as well, but obviously there is no back and forth dialogue with you.
Why don't you switch over to the Berger 185 BTLR and give up on those 175 SMK's if you want to shoot 1000 yards. Yeah... I started with the 175's at 1000 awhile ago and I guess I could have spent alot of time doing your so-called tweak, but the bullet is weak. Why do push them them so hard? That should tell you they don't work all that well. A 185 will get the job done all year long at 1000 yards in all temps at less than 2600 fps MV which the .308 likes alot. Good shooting.
PS - FYI - I can put a CCB shot at less than 1 MOA at 1000 yards anytime, anyday, so don't bust on us F Class Shooters. The arrogance is deafening.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">So, why do these program allow and help you run the actual numbers... and tweak the G7...we found the proper G7 to be .237, seem odd for something not subject to muzzle velocity variations.
we didn't use standard pressure it was inputted and calculated in real time. We went straight from chronograph to 1000 yards with it, using more than one rifle. Our Kestrels were dead nuts on.
What do you think I was using a stock Remington, how about a custom GAP... Bartlein barrel with less than 1500 rounds down the tube. MV 2770fps SD was less than 10...
As I said we recorded everything
Maybe you have no idea how to work a program if you can't get the G1 to work, not to mention the above data was from Lapua test, I doubt they compared with Doppler and didn't know how to input the data... clearly the data posted speaks for itself, it was raw data...unadjusted.
Let me guess, you shot F Class and know Bryan so you rule the world, nobody knows how to do this but you. Cause I have no clue and information I have comes from someone other than Bryan so it has to be wrong.
Fuck, in F Class you get sighters, if you can't hit a 6X6 target board and get on target I don't what you know. Any fool can run JBM and get on paper even at 1000 yards, G1 or anything else, Telling me you didn't use any sighters prior to score. </div></div>
I tried to have a civil conversation with you but I see that isn't working. You brought up a few good points, Bryan did as well, but obviously there is no back and forth dialogue with you.
Why don't you switch over to the Berger 185 BTLR and give up on those 175 SMK's if you want to shoot 1000 yards. Yeah... I started with the 175's at 1000 awhile ago and I guess I could have spent alot of time doing your so-called tweak, but the bullet is weak. Why do push them them so hard? That should tell you they don't work all that well. A 185 will get the job done all year long at 1000 yards in all temps at less than 2600 fps MV which the .308 likes alot. Good shooting.
PS - FYI - I can put a CCB shot at less than 1 MOA at 1000 yards anytime, anyday, so don't bust on us F Class Shooters. The arrogance is deafening.
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">And is MV dependent, like anything else.</div></div>
Yes, you do have to use accurate inputs if you expect accurate output, but that's not relevant to the G1 vs G7 discussion.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Clearly the way Ballistics FTE processes it, and Bulletflight for example, because the two offer two different answers to the same questions.</div></div>
It's true that programs don't always agree. This, also, is not really relevant to the G1 vs G7 discussion. JBM is a properly written program. The closer your solver matches it given identical inputs, the more accurate your solver is. Any difference between a given solver and JBM can be viewed as error in the other solver.
I'll assume you're talking about the 175 SMK with G7 BC's of .237 and .243? Here's a case in point. I worked a little with the developer of BulletFlight early on, giving some hints on how to set up his solver properly, etc. You say it needed a G7 BC of .243 to predict an accurate trajectory to 1000, and that's exactly the BC I measured for that bullet. I'd say in the case of these two solvers, BulletFlight is closer to the 'proper' solution (I'd be interested to know how each compares to JBM). BTW, .237 and .243 are only different by 2.5%, which happens to be almost exactly the error one would incur if the program uses an atmosphere model (ASM vs ICAO) other than what the BC's are corrected for. In other words (assuming your data is accurate within 2.5%), Bullet flight is the more accurate of the two programs because it uses the same atmosphere that the BC's are corrected for, and FTE has a mismatch. That means .243 is the right BC, and the 'accurate' solution you got with .237 was the result of offsetting errors.
It's either that, or something else. But what do I know, I'm just a Ballistician.
-Bryan
BTW, take it easy on the F-class guys. Their discipline might not require first shot hits. But when they come off the line after a 20 shot string, they have a very good idea of what the <span style="font-style: italic">correct</span> elevation was for a given range. Much more so, I argue, than another shooter who might only put 5 or 3 or even 1 shot on a target. KD shooting is not synonymous with 'ignorant of ballistics'.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">And is MV dependent, like anything else.</div></div>
Yes, you do have to use accurate inputs if you expect accurate output, but that's not relevant to the G1 vs G7 discussion.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Clearly the way Ballistics FTE processes it, and Bulletflight for example, because the two offer two different answers to the same questions.</div></div>
It's true that programs don't always agree. This, also, is not really relevant to the G1 vs G7 discussion. JBM is a properly written program. The closer your solver matches it given identical inputs, the more accurate your solver is. Any difference between a given solver and JBM can be viewed as error in the other solver.
I'll assume you're talking about the 175 SMK with G7 BC's of .237 and .243? Here's a case in point. I worked a little with the developer of BulletFlight early on, giving some hints on how to set up his solver properly, etc. You say it needed a G7 BC of .243 to predict an accurate trajectory to 1000, and that's exactly the BC I measured for that bullet. I'd say in the case of these two solvers, BulletFlight is closer to the 'proper' solution (I'd be interested to know how each compares to JBM). BTW, .237 and .243 are only different by 2.5%, which happens to be almost exactly the error one would incur if the program uses an atmosphere model (ASM vs ICAO) other than what the BC's are corrected for. In other words (assuming your data is accurate within 2.5%), Bullet flight is the more accurate of the two programs because it uses the same atmosphere that the BC's are corrected for, and FTE has a mismatch. That means .243 is the right BC, and the 'accurate' solution you got with .237 was the result of offsetting errors.
It's either that, or something else. But what do I know, I'm just a Ballistician.
-Bryan
BTW, take it easy on the F-class guys. Their discipline might not require first shot hits. But when they come off the line after a 20 shot string, they have a very good idea of what the <span style="font-style: italic">correct</span> elevation was for a given range. Much more so, I argue, than another shooter who might only put 5 or 3 or even 1 shot on a target. KD shooting is not synonymous with 'ignorant of ballistics'.
Re: G1, G7 Ballistics Coeficient?
Leaddog,
Arrogance, please, before Bryan chimed in, you had me not knowing what atmospheric pressure was, or how to input anything in a ballistic computer, once Bryan realized I had a frame of reference you changed your tune, so dont' attempt to lecture me on arrogance.
Trust me when I say, I have no problem hitting targets at distance. And I use a variety of bullets. It's the F Class shooters who think they rule the world, or at least the terrain between their car and the firing line. I have shot F Class on more than one occasion and understand the benefits of it.
So do me a favor LD, buzz off because all of the sudden i brought up good points but before I was an idiot -- so who is showing who what ?
Bryan
Nothing more than a 175SMK, 2770fps, Ballistics gives it a .252, Bulletflight says, "hidden" so I can't tell you what is in the "Bryan Litz Library" but after using the calculator it was changed to .243. Ballistics needed .237 to match real world data.
And I sort of think all this in important because the solution is matters. If I can take my known information for G1 and get closer to center than unknown G7 information that is important. If both the G7 and G1 needs adjustment, large or small but then both gives me a reliable output, that matters.
No magic, no voodoo, and sure while there is garbage in, garbage out, there is also what you know and what you don't. G1 has been around a long time, people know by now starting with .496 is better than starting with .505.. so the history helps make the hits.
My thing is, people, like yourself are disagreeing on several key points, and not just with Gus, there is Gerald, too. I try to keep an open mind and absorb a bit of everything I can, then I go out and try it. Because I don't take people's word blindly doesn't mean I am disrespectful, just means I am curious as to why, because I want to know and see it. If it was drop dead accurate, and I could repeat it in the field, you got me. if I can't I need to know more.
Leaddog,
Arrogance, please, before Bryan chimed in, you had me not knowing what atmospheric pressure was, or how to input anything in a ballistic computer, once Bryan realized I had a frame of reference you changed your tune, so dont' attempt to lecture me on arrogance.
Trust me when I say, I have no problem hitting targets at distance. And I use a variety of bullets. It's the F Class shooters who think they rule the world, or at least the terrain between their car and the firing line. I have shot F Class on more than one occasion and understand the benefits of it.
So do me a favor LD, buzz off because all of the sudden i brought up good points but before I was an idiot -- so who is showing who what ?
Bryan
Nothing more than a 175SMK, 2770fps, Ballistics gives it a .252, Bulletflight says, "hidden" so I can't tell you what is in the "Bryan Litz Library" but after using the calculator it was changed to .243. Ballistics needed .237 to match real world data.
And I sort of think all this in important because the solution is matters. If I can take my known information for G1 and get closer to center than unknown G7 information that is important. If both the G7 and G1 needs adjustment, large or small but then both gives me a reliable output, that matters.
No magic, no voodoo, and sure while there is garbage in, garbage out, there is also what you know and what you don't. G1 has been around a long time, people know by now starting with .496 is better than starting with .505.. so the history helps make the hits.
My thing is, people, like yourself are disagreeing on several key points, and not just with Gus, there is Gerald, too. I try to keep an open mind and absorb a bit of everything I can, then I go out and try it. Because I don't take people's word blindly doesn't mean I am disrespectful, just means I am curious as to why, because I want to know and see it. If it was drop dead accurate, and I could repeat it in the field, you got me. if I can't I need to know more.
Re: G1, G7 Ballistics Coeficient?
Frank,
I think I was editing as you were typing. Please see above assessment of the 175 SMK.
What I think your account demonstrates is, when you use the right BC for that bullet (.243), in conjunction with a 'proper' solver (BulletFlight) in a carefully executed test, the accuracy of a G7 based solution is very good. Any excursion from that (like using .243 in LB3, which interprets that number differently than intended) will produce a different result.
-Bryan
Frank,
I think I was editing as you were typing. Please see above assessment of the 175 SMK.
What I think your account demonstrates is, when you use the right BC for that bullet (.243), in conjunction with a 'proper' solver (BulletFlight) in a carefully executed test, the accuracy of a G7 based solution is very good. Any excursion from that (like using .243 in LB3, which interprets that number differently than intended) will produce a different result.
-Bryan
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Leaddog,
Arrogance, please, before Bryan chimed in, you had me not knowing what atmospheric pressure was, or how to input anything in a ballistic computer, once Bryan realized I had a frame of reference you changed your tune, so dont' attempt to lecture me on arrogance.
Trust me when I say, I have no problem hitting targets at distance. And I use a variety of bullets. It's the F Class shooters who think they rule the world, or at least the terrain between their car and the firing line. I have shot F Class on more than one occasion and understand the benefits of it.
So do me a favor LD, buzz off because all of the sudden i brought up good points but before I was an idiot -- so who is showing who what ?
</div></div>
Not sure why you feel the need to be so defensive here, LL.
And for for your information, I humped an M16 in Vietnam 1969-70, so I know a bit more than just F Class shooting which you think is second class citizenry. I'm done with this thread. Have a good night.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Leaddog,
Arrogance, please, before Bryan chimed in, you had me not knowing what atmospheric pressure was, or how to input anything in a ballistic computer, once Bryan realized I had a frame of reference you changed your tune, so dont' attempt to lecture me on arrogance.
Trust me when I say, I have no problem hitting targets at distance. And I use a variety of bullets. It's the F Class shooters who think they rule the world, or at least the terrain between their car and the firing line. I have shot F Class on more than one occasion and understand the benefits of it.
So do me a favor LD, buzz off because all of the sudden i brought up good points but before I was an idiot -- so who is showing who what ?
</div></div>
Not sure why you feel the need to be so defensive here, LL.
And for for your information, I humped an M16 in Vietnam 1969-70, so I know a bit more than just F Class shooting which you think is second class citizenry. I'm done with this thread. Have a good night.
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">No magic, no voodoo, and sure while there is garbage in, garbage out, there is also what you know and what you don't. G1 has been around a long time, people know by now starting with .496 is better than starting with .505.. so the history helps make the hits. </div></div>
This is a very good point. I knew right from the beginning that attempting a paradigm shift from G1 to G7 wouldn't be easy because everyone was familiar with G1. Knowing that G7 was better, I did my best to put all the necessary pieces in place (library of G7 BC's, program(s) that used them properly, literature explaining the difference, etc) Even with all that in place, paradigm shifts are still hard and it will take a long time before G7 BC's are as known and commonly known as G1's.
On that note, did you notice that Lapua now gives G7 BC's for their bullets:
http://www.lapua.com/en/products/reloading/bullets/centerfire-rifle-bullets/8
Now why would a company with access to such a vast database of radar data choose to offer G7 BC's for their LR bullets?
Not the 'nail in the coffin' by a long shot, just another fact for you to consider among all the rest.
-Bryan
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">No magic, no voodoo, and sure while there is garbage in, garbage out, there is also what you know and what you don't. G1 has been around a long time, people know by now starting with .496 is better than starting with .505.. so the history helps make the hits. </div></div>
This is a very good point. I knew right from the beginning that attempting a paradigm shift from G1 to G7 wouldn't be easy because everyone was familiar with G1. Knowing that G7 was better, I did my best to put all the necessary pieces in place (library of G7 BC's, program(s) that used them properly, literature explaining the difference, etc) Even with all that in place, paradigm shifts are still hard and it will take a long time before G7 BC's are as known and commonly known as G1's.
On that note, did you notice that Lapua now gives G7 BC's for their bullets:
http://www.lapua.com/en/products/reloading/bullets/centerfire-rifle-bullets/8
Now why would a company with access to such a vast database of radar data choose to offer G7 BC's for their LR bullets?
Not the 'nail in the coffin' by a long shot, just another fact for you to consider among all the rest.
-Bryan
Re: G1, G7 Ballistics Coeficient?
Seeing it more and more is a good thing, and a broader library can only help, that an access to the numbers in a variety of places is important, as it begins to build a personal database of the information so it can be used more.
Especially when you have programs like the Apps that have a less than complete library. Being able to access it in the field is important because not everyone carries the book with them. I think it makes sense for Lapua to offer it, as people want to use it and there is no reason they shouldn't, as long as they know how.
I found with either using the program, like Bulletflight to start with the library then take the actual field data and tweak the numbers to give you a better number that more closely matches your actual numbers then you can change the BC in the program and you'll be that much better off. It's the same either way, but like Lindy says, it's really the Transonic region you want to know about so the G7 curve in these programs is closer once you adjust it.
Tell you friend Leaddog, I'm not impressed and next don't assume I'm an idiot without the most basic of knowledge, he came to your defense unarmed in this case. Carrying an M16 nothing great, I carried one too, that and $3 I can get a coffee at Starbucks.
My advice would be to offer the G7 numbers for greater distribution, because if I know it I'll use it, if not G1 is easier to find. I don't think "hidden" helps anyone.
Seeing it more and more is a good thing, and a broader library can only help, that an access to the numbers in a variety of places is important, as it begins to build a personal database of the information so it can be used more.
Especially when you have programs like the Apps that have a less than complete library. Being able to access it in the field is important because not everyone carries the book with them. I think it makes sense for Lapua to offer it, as people want to use it and there is no reason they shouldn't, as long as they know how.
I found with either using the program, like Bulletflight to start with the library then take the actual field data and tweak the numbers to give you a better number that more closely matches your actual numbers then you can change the BC in the program and you'll be that much better off. It's the same either way, but like Lindy says, it's really the Transonic region you want to know about so the G7 curve in these programs is closer once you adjust it.
Tell you friend Leaddog, I'm not impressed and next don't assume I'm an idiot without the most basic of knowledge, he came to your defense unarmed in this case. Carrying an M16 nothing great, I carried one too, that and $3 I can get a coffee at Starbucks.
My advice would be to offer the G7 numbers for greater distribution, because if I know it I'll use it, if not G1 is easier to find. I don't think "hidden" helps anyone.
Re: G1, G7 Ballistics Coeficient?
Coming in a little late to this but I have been using G1 BCs through JBM for years with every long range bullet, AMAX/VLD/SMK/etc, I have used and shot out to 1600 yards using them and never had any problems. Out to 1000 yards I have never been off more than .2 mils and it's usually less than that. Even the longer stuff wasn't much farther off. Definitely in the the area to get you on target.
G7 might be better but I will continue to use what I know works through my experience.
Coming in a little late to this but I have been using G1 BCs through JBM for years with every long range bullet, AMAX/VLD/SMK/etc, I have used and shot out to 1600 yards using them and never had any problems. Out to 1000 yards I have never been off more than .2 mils and it's usually less than that. Even the longer stuff wasn't much farther off. Definitely in the the area to get you on target.
G7 might be better but I will continue to use what I know works through my experience.
Re: G1, G7 Ballistics Coeficient?
Fascinating discussion. Here is my take. The G7 is probably the better standard. The problem is that people have been using the G1 standard for so long, clever people have figured out how to work around the standard by using fudge factors to make it work, so it does not surprise me that a model using G1 for a well-known projectile that is appropriately modified would come up with better results in the field, which is all LL cares about. I believe that one could start with a model based on the G7 standard and come up with something even better if they ran with it.
All that said, it is difficult to develop a new standard. The classic example is the QWERTY keyboard. The QWERTY keyboard was developed to slow down typists because they were typing so fast that the keys in the old typewriters were getting tangled up. The slower design helped typists to maintain rhythm without sticking the keys.
Today, with computers, the reasoning for the original QWERTY design makes no sense. The DVORAK design is much superior. What am I typing this post with right now? A QUERTY keyboard. Apparently, typist pools never wanted to be retrained on the DVORAK once typewriter designs improved. And companies making typing implements found that consumers were used to QWERTY. Texas Instruments built a computer with an ABC keyboard and it went over like a lead balloon. Even the advent of a new technology (computers) wasn't enough to get people to change.
As an ironic side note... Bryan sells a G7-based ballistic program (MOBALL) built into a Texas Instruments graphing calculator. Which brings us back to G7. I think that G7 is an incremental enough change and there is enough momentum behind it to change the way that people write ballistic programs. JBM using G7 and being available for free along with Shooter being available on the Android for an affordable price creates some opportunities for the G7 to take root. Eventually, someone might sink some real money into developing around the G7 to "fix" it to better reflect the real world, and we might see it coming out ahead.
For now, G7 makes sense if for no other reason than to make choices between projectiles and calibers. In some cases, the G1 and G7 are flipped in terms of which projectile has a higher BC. In those cases, I will believe the G7 tested by an unbiased (OK, relatively unbiased) third party.
Fascinating discussion. Here is my take. The G7 is probably the better standard. The problem is that people have been using the G1 standard for so long, clever people have figured out how to work around the standard by using fudge factors to make it work, so it does not surprise me that a model using G1 for a well-known projectile that is appropriately modified would come up with better results in the field, which is all LL cares about. I believe that one could start with a model based on the G7 standard and come up with something even better if they ran with it.
All that said, it is difficult to develop a new standard. The classic example is the QWERTY keyboard. The QWERTY keyboard was developed to slow down typists because they were typing so fast that the keys in the old typewriters were getting tangled up. The slower design helped typists to maintain rhythm without sticking the keys.
Today, with computers, the reasoning for the original QWERTY design makes no sense. The DVORAK design is much superior. What am I typing this post with right now? A QUERTY keyboard. Apparently, typist pools never wanted to be retrained on the DVORAK once typewriter designs improved. And companies making typing implements found that consumers were used to QWERTY. Texas Instruments built a computer with an ABC keyboard and it went over like a lead balloon. Even the advent of a new technology (computers) wasn't enough to get people to change.
As an ironic side note... Bryan sells a G7-based ballistic program (MOBALL) built into a Texas Instruments graphing calculator. Which brings us back to G7. I think that G7 is an incremental enough change and there is enough momentum behind it to change the way that people write ballistic programs. JBM using G7 and being available for free along with Shooter being available on the Android for an affordable price creates some opportunities for the G7 to take root. Eventually, someone might sink some real money into developing around the G7 to "fix" it to better reflect the real world, and we might see it coming out ahead.
For now, G7 makes sense if for no other reason than to make choices between projectiles and calibers. In some cases, the G1 and G7 are flipped in terms of which projectile has a higher BC. In those cases, I will believe the G7 tested by an unbiased (OK, relatively unbiased) third party.
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Bryan sells a G7-based ballistic program (MOBALL) built into a Texas Instruments graphing calculator.</div></div>
I don't think that's being offered any more - Bryan had a problem with them.
In any case, I've used both G1 and G7 and found it necessary to "tweak" both. Some of the reasons why that's necessary may be found in Sources of Ballistic Program Inaccuracies.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Bryan sells a G7-based ballistic program (MOBALL) built into a Texas Instruments graphing calculator.</div></div>
I don't think that's being offered any more - Bryan had a problem with them.
In any case, I've used both G1 and G7 and found it necessary to "tweak" both. Some of the reasons why that's necessary may be found in Sources of Ballistic Program Inaccuracies.
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Bryan sells a G7-based ballistic program (MOBALL) built into a Texas Instruments graphing calculator.</div></div>
I don't think that's being offered any more - Bryan had a problem with them.
In any case, I've used both G1 and G7 and found it necessary to "tweak" both. Some of the reasons why that's necessary may be found in Sources of Ballistic Program Inaccuracies.
</div></div>
I think LowLight had all of those things knocked in his side-by-side comparisons using Doppler radar. We are really talking about the core model at this point, not on setting up a program correctly, which your article covers very well.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Bryan sells a G7-based ballistic program (MOBALL) built into a Texas Instruments graphing calculator.</div></div>
I don't think that's being offered any more - Bryan had a problem with them.
In any case, I've used both G1 and G7 and found it necessary to "tweak" both. Some of the reasons why that's necessary may be found in Sources of Ballistic Program Inaccuracies.
</div></div>
I think LowLight had all of those things knocked in his side-by-side comparisons using Doppler radar. We are really talking about the core model at this point, not on setting up a program correctly, which your article covers very well.
Re: G1, G7 Ballistics Coeficient?
I don't use any fudge factors. I punch my numbers in JBM using the G1 BCs provided and get the right answers. Simple. No voodoo or magic.
People just love new shit and the G7 is the new must use thing but the only problem is it's not must use.
I don't use any fudge factors. I punch my numbers in JBM using the G1 BCs provided and get the right answers. Simple. No voodoo or magic.
People just love new shit and the G7 is the new must use thing but the only problem is it's not must use.
Re: G1, G7 Ballistics Coeficient?
I agree with Rob01.
Everybody is looking for magic then go to a magic show.
I agree with Rob01.
Everybody is looking for magic then go to a magic show.
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rob01</div><div class="ubbcode-body">I don't use any fudge factors. I punch my numbers in JBM using the G1 BCs provided and get the right answers. Simple. No voodoo or magic.
People just love new shit and the G7 is the new must use thing but the only problem is it's not must use.</div></div>
I was talking about fudge factors used inside of the ballistic model. JBM is a plain jane ballistic model. If you are using it, you are better off with G7, but there probably won't be much departure (between G1 and G7) until you get close to the transonic region. It's at the margins that G1 stops modelling effectively. If you buy Bryan's book, you can see what the two curves look like as well as what the reality looks like.
My understanding is that Loadbase uses a different set of equations. When I say "fudge factor," I am talking about what is going on inside of the model, not what shooters are doing with it to make it match up.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rob01</div><div class="ubbcode-body">I don't use any fudge factors. I punch my numbers in JBM using the G1 BCs provided and get the right answers. Simple. No voodoo or magic.
People just love new shit and the G7 is the new must use thing but the only problem is it's not must use.</div></div>
I was talking about fudge factors used inside of the ballistic model. JBM is a plain jane ballistic model. If you are using it, you are better off with G7, but there probably won't be much departure (between G1 and G7) until you get close to the transonic region. It's at the margins that G1 stops modelling effectively. If you buy Bryan's book, you can see what the two curves look like as well as what the reality looks like.
My understanding is that Loadbase uses a different set of equations. When I say "fudge factor," I am talking about what is going on inside of the model, not what shooters are doing with it to make it match up.
Re: G1, G7 Ballistics Coeficient?
This is nothing you should listen to statisticians argue about their seasonal adjustment models or data disclosure control programs
...
All Gs are models none 100% accurate and as has been said they work (one way or the other). I agree with Bryan (good book btw really enjoyed it) on accuracy of models especially in transonic region of flight however first there must be an education and broader knowledge before one can accept another novelty (which than becomes a standard). I think we attribute too much relevance as to which model is being used.
This is nothing you should listen to statisticians argue about their seasonal adjustment models or data disclosure control programs
All Gs are models none 100% accurate and as has been said they work (one way or the other). I agree with Bryan (good book btw really enjoyed it) on accuracy of models especially in transonic region of flight however first there must be an education and broader knowledge before one can accept another novelty (which than becomes a standard). I think we attribute too much relevance as to which model is being used.
Re: G1, G7 Ballistics Coeficient?
The " true " sometimes.. is in the middle of the way...... but I agree with Frank.. about " One number is big the other is smaller..."
I've used a lot of softwares, I can get basically the same dope using a G1 or G7...
THE MOST IMPORTANT THING IS ( for me ) how you can able to collect the datas, how accurate are your instruments, how you are able to understand basic rules...
how you are able to handle what Lindy's say about the inaccuracies of ballistic software..
your scope works correct ?
your nominal clicks are the same on the actual clicks ?
ecc ecc
PEOPLE PUT ON THE SOFTWARE THE DATAS IN THE RIGHT WAY ?
for example the difference between station pressure and barometric pressure is not clear to all.... ( specially in Italy )
The best software for me is Field Firing Solutions version IV LE, I put one PVM-08 crono at 10 meters to get muzzle, the other one at 300 meters.... ( sometimes till 500 meters )... I can have for same bullet 2 speeds, with these I calculate a BC using FFS software, I tune it with DK function.... I obtain a " modified G1 "...... but it's works great.
I take the same values of speed and I put theme in JBM using the software to calculate a G7 BC ...... and after I do a ballistic table with JBM the dope founded in the same.....
JMB with G7
FFS with modified G1
I compare the data with the FDAC from Adaptive and the data match..
I've tested a lot my load always dead on....
I've do some works for Italian special forces and they are testing my ballistic tables from Kosovo to Afghanistan and they are always dead on....
Actually I'm doing the same thing for a .408 ..works in progress, at the moment I'm satisfied..
to have one more option to compare data for .50, .408 and .375 we are going to use this system
very close to doppler data...
Some times people say G1 doesn't works..... better G7... but they are going to check the dope with a cheaper scope, cheaper rifle, bad load .... so nothing in the correct way...... but the flow is.... G7 IS BETTER....
The " true " sometimes.. is in the middle of the way...... but I agree with Frank.. about " One number is big the other is smaller..."
I've used a lot of softwares, I can get basically the same dope using a G1 or G7...
THE MOST IMPORTANT THING IS ( for me ) how you can able to collect the datas, how accurate are your instruments, how you are able to understand basic rules...
how you are able to handle what Lindy's say about the inaccuracies of ballistic software..
your scope works correct ?
your nominal clicks are the same on the actual clicks ?
ecc ecc
PEOPLE PUT ON THE SOFTWARE THE DATAS IN THE RIGHT WAY ?
for example the difference between station pressure and barometric pressure is not clear to all.... ( specially in Italy )
The best software for me is Field Firing Solutions version IV LE, I put one PVM-08 crono at 10 meters to get muzzle, the other one at 300 meters.... ( sometimes till 500 meters )... I can have for same bullet 2 speeds, with these I calculate a BC using FFS software, I tune it with DK function.... I obtain a " modified G1 "...... but it's works great.
I take the same values of speed and I put theme in JBM using the software to calculate a G7 BC ...... and after I do a ballistic table with JBM the dope founded in the same.....
JMB with G7
FFS with modified G1
I compare the data with the FDAC from Adaptive and the data match..
I've tested a lot my load always dead on....
I've do some works for Italian special forces and they are testing my ballistic tables from Kosovo to Afghanistan and they are always dead on....
Actually I'm doing the same thing for a .408 ..works in progress, at the moment I'm satisfied..
to have one more option to compare data for .50, .408 and .375 we are going to use this system
very close to doppler data...
Some times people say G1 doesn't works..... better G7... but they are going to check the dope with a cheaper scope, cheaper rifle, bad load .... so nothing in the correct way...... but the flow is.... G7 IS BETTER....
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NTRP-CKA</div><div class="ubbcode-body">I just write down where the bullet hits. </div></div>
Yes, I do that too.......
But interestingly, when I confirmed by actually shooting my load, at the max range I had available (900 yds):
JBM using using the G7 Model
900 Yds Drop -7.5 Mils drift 1.8 Mils
JBM Using the G1 Model
900 Yds Drop -7.4 Mils Drift 1.7 MILS
My actual data was between the two models or about 0.05 Mils difference. Since I cannot dial finer than 0.1 Mils, I could use either and adjust my aim points.
But here's where it becomes flaky. I have not been able to shoot this load further than 900 yds. to confirm. But if I use JBM's data at 1300 yds, and the load is still transonic this is what I see:
G7 Model
1300 Yds Drop -14.4 Mils Drift 3.0 Mils
G1 Model
1300 Yds Drop -14.0 Mils Drift 2.8 Mils
Now the elevation differences is almost 19" between the two models. One or both has to be wrong.......
I'd guess I'd just split the difference, and test it, when and if I get to shoot that far.
Bob
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NTRP-CKA</div><div class="ubbcode-body">I just write down where the bullet hits. </div></div>
Yes, I do that too.......
But interestingly, when I confirmed by actually shooting my load, at the max range I had available (900 yds):
JBM using using the G7 Model
900 Yds Drop -7.5 Mils drift 1.8 Mils
JBM Using the G1 Model
900 Yds Drop -7.4 Mils Drift 1.7 MILS
My actual data was between the two models or about 0.05 Mils difference. Since I cannot dial finer than 0.1 Mils, I could use either and adjust my aim points.
But here's where it becomes flaky. I have not been able to shoot this load further than 900 yds. to confirm. But if I use JBM's data at 1300 yds, and the load is still transonic this is what I see:
G7 Model
1300 Yds Drop -14.4 Mils Drift 3.0 Mils
G1 Model
1300 Yds Drop -14.0 Mils Drift 2.8 Mils
Now the elevation differences is almost 19" between the two models. One or both has to be wrong.......
I'd guess I'd just split the difference, and test it, when and if I get to shoot that far.
Bob
Re: G1, G7 Ballistics Coeficient?
G1 is a measure of how much a given projectile differs from Standard Type 1 projectile. G7 is a measure of how much a given projectile differs from Standard Type 7 projectile. Each of the Standard Projectiles has a Standard Drag Curve computed for it.
Bullets like SMK fit Type 7 shape almost perfectly but are quite different from Type 1 shape.
Thus <span style="text-decoration: underline">in theory</span> - for an SMK bullet prediction based on Type 1 model (G1 curve and G1 BC) should at the very least be noticeably less accurate than prediction based on Type 7 model (G7 drag curve and G7 BC).
<span style="font-weight: bold">Bryan and whoever else wants to try</span> - could you please explain why practical results seem to prove the opposite, i.e. that there's almost no difference between the two? Math took a vacation?
It was my understanding that:
<ul style="list-style-type: disc">[*]Pejsa equations were for supersonic only.[*]G1 and G7 coefficients make sense only in relation to Type 1 or Type 7 standard projectiles correspondingly, and have no meaning outside of those.[*]Gn coefficients make sense only when the bullet in question resembles the standard projectile fairly closely, otherwise - if the bullet is really much different - the whole thing should collapse.[/list]
Could you please explain what's wrong (and why) in the above statements? And how can Gus use G1 (which tells how different the bullet is from a standard projectile) if he doesn't use standard projectile's drag curve (as Pejsa equations don't refer to any of the standard drag curves)?
Tnx!
G1 is a measure of how much a given projectile differs from Standard Type 1 projectile. G7 is a measure of how much a given projectile differs from Standard Type 7 projectile. Each of the Standard Projectiles has a Standard Drag Curve computed for it.
Bullets like SMK fit Type 7 shape almost perfectly but are quite different from Type 1 shape.
Thus <span style="text-decoration: underline">in theory</span> - for an SMK bullet prediction based on Type 1 model (G1 curve and G1 BC) should at the very least be noticeably less accurate than prediction based on Type 7 model (G7 drag curve and G7 BC).
<span style="font-weight: bold">Bryan and whoever else wants to try</span> - could you please explain why practical results seem to prove the opposite, i.e. that there's almost no difference between the two? Math took a vacation?
It was my understanding that:
<ul style="list-style-type: disc">[*]Pejsa equations were for supersonic only.[*]G1 and G7 coefficients make sense only in relation to Type 1 or Type 7 standard projectiles correspondingly, and have no meaning outside of those.[*]Gn coefficients make sense only when the bullet in question resembles the standard projectile fairly closely, otherwise - if the bullet is really much different - the whole thing should collapse.[/list]
Could you please explain what's wrong (and why) in the above statements? And how can Gus use G1 (which tells how different the bullet is from a standard projectile) if he doesn't use standard projectile's drag curve (as Pejsa equations don't refer to any of the standard drag curves)?
Tnx!
Re: G1, G7 Ballistics Coeficient?
Mouse brings up great points... and from my personal experience both LB3 and FFS are the two best ballistic programs on the market. Gus says he is not using straight up Pesja, but he is also not using Point Mass like Bryan uses. Of which Bryan disagrees with as stated above. However the results are unmistakable, clearly looking the data provided next to Doppler the non-Point Mass solutions are so close as to call it a tie. Why or how can you disagree with something that clearly produces excellent end results ?
I have said what Mouse has on more than one occasion, how can "math" take a vacation and work for one and not all... seems un-math like.
Guys going out and shooting this, not just on the square range find one is not
"better" than the other, just different. FFS or LB3 with G1, JBM w/ G7 or even the FDAC each produce repeatable results that equal the same thing, a hit on target. So where is the magic ... ?
Mouse brings up great points... and from my personal experience both LB3 and FFS are the two best ballistic programs on the market. Gus says he is not using straight up Pesja, but he is also not using Point Mass like Bryan uses. Of which Bryan disagrees with as stated above. However the results are unmistakable, clearly looking the data provided next to Doppler the non-Point Mass solutions are so close as to call it a tie. Why or how can you disagree with something that clearly produces excellent end results ?
I have said what Mouse has on more than one occasion, how can "math" take a vacation and work for one and not all... seems un-math like.
Guys going out and shooting this, not just on the square range find one is not
"better" than the other, just different. FFS or LB3 with G1, JBM w/ G7 or even the FDAC each produce repeatable results that equal the same thing, a hit on target. So where is the magic ... ?
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Bryan and whoever else wants to try - could you please explain why practical results seem to prove the opposite, i.e. that there's almost no difference between the two? Math took a vacation?</div></div>
That's a good question, and is the question behind why it will take a long time for the paradigm to shift to G7. The answer is that for a great deal of the supersonic range of the bullets flight, the two curves (G1 and G7) are very similar. As a result, there is negligible difference up to 600 yards, minor difference from there to 800 or so, then depending on the round you're shooting, the error starts to become more significant. The majority of shooters are not routinely shooting at ranges where the difference between G1 and G7 based trajectories is huge. So that's the answer to the question: 'why doesn't one appear better than the other'. Be assured that if you shoot far enough, often enough, and all your other variables are known with a high degree of certainty, the G7 based predictions will result in better centered groups on average. Remember, drop 'observations' are subject to all kinds of potential error which I won't list here. It's no surprise that one method doesn't immediately shine over another when there's so much uncertainty with everything else. In other words, the 'signal to noise' ratio is low. But there is a signal, and that signal is that G7 based trajectories are better, even if it's difficult to resolve amongst the static in the environment.
The problem with Pejsa based programs is that no two programmers write them the same way. Especially around transonic, those solvers are all unique to their creators. That flexibility is a good thing if you're writing a program for yourself, or you're trying to match a particular set of radar data. It even makes very strong believers out of people who see the comparison. The flexibility of the pejsa solver becomes a problem when you consider that none of these programs respond the same way to inputs. None of them interpret BC the same way.
The irony is blinding here. The pejsa equations allow the programmer to depart from the G1 curve to something more suitable for LR bullets. So he makes the curve look much more like a G7 curve. But the program still accepts 'G1' BCs, then basically puts it on a G7 curve behind the scenes. The users perception is that "this is a G1 program that gives similar or better results than a G7 program!" It's got the advantage of accepting G1 inputs which makes people 'comfortable', and the smarts to interpret it something like G7.
So why is that a bad thing? The reason it's bad is because not all the pejsa programs do their 'mojo' the same. Some make the curve steeper, some more shallow, some splice their transonic mojo sooner than others, etc etc. All the while, they're all interpreting BC differently than a 'properly written' program which refers to the real G1 or G7 standard. The consequence is that the pejsa based programs will not interpret a BC (G1 or G7) the same as any other program on the planet, even other pejsa programs. So you're forced to tweak them to match your data set.
By contrast, if you're using a conventional point mass solver that refers to an actual standard curve, then that program will agree with any other properly written program when given the same inputs. Why is that valuable? <span style="font-style: italic"><span style="font-weight: bold">Because then the world can agree on what the true BC is for a given bullet</span></span>. Being able to lock down a BC for a bullet is incredibly valuable for many reasons. One is it allows apples-to-apples comparisons between bullets, another reason is that it allows a shooter with no historical data on a bullet to represent it's performance accurately from the get-go, rather than needing to shoot it at many ranges before his program gets 'tuned in'.
If everyone's using their different flavors of half baked pejsa solvers that were tweaked to match different unique data sets, those solvers (all being different) will require different descriptions for the same bullet to get the right answer. Sounds like anarchy to me.
LL provided the perfect example above with his account of the different programs requiring different BC's to arrive at the same correct solution. The program that was written properly (BulletFlight) gave the correct answer when given the correct BC, without needing tweaked at all from the BC I assessed for that bullet. That is a perfect example of how things can work if you use proper solvers and BC's that work together according to how the equations of motion are solved.
The pejsa based programs are all so different and you really do have to tweak them because they don't all interpret BC the same way. It's a problem of standardization, and it's why those programs aren't the best solution if you need a predictive tool. If you just want a tool to tell you what you shot after you already shot it, those tools have the flexibility to do that for you. However if you want the best chance to be on target with a bullet you never fired before, you need a program that will interpret the BC properly, according to the standard, with no mojo, voodoo, or in any way other than how it was intended.
Contrary to popular belief, you don't have to shoot 100's of rounds before you can start being accurate with your ballistic predictions. Marksmanship, yes. Practice at every opportunity. But ballistics is a very mature science that's ready for application from the first shot. Every shooter doesn't have to re-invent the wheel. Just use the right data and tools for the job and focus on shooting. If LL would have done this, he would have been on target from shot #1, using a G7 BC of .243 for the 175 SMK in the right solver.
Granted, it can be difficult for shooters to know which programs are properly written, and apply BC's as intended. Maybe I should make a list.
Rest assured, math didn't take a vacation, and there is no magic involved. We, as shooters, just need to know what to look for.
-Bryan
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Bryan and whoever else wants to try - could you please explain why practical results seem to prove the opposite, i.e. that there's almost no difference between the two? Math took a vacation?</div></div>
That's a good question, and is the question behind why it will take a long time for the paradigm to shift to G7. The answer is that for a great deal of the supersonic range of the bullets flight, the two curves (G1 and G7) are very similar. As a result, there is negligible difference up to 600 yards, minor difference from there to 800 or so, then depending on the round you're shooting, the error starts to become more significant. The majority of shooters are not routinely shooting at ranges where the difference between G1 and G7 based trajectories is huge. So that's the answer to the question: 'why doesn't one appear better than the other'. Be assured that if you shoot far enough, often enough, and all your other variables are known with a high degree of certainty, the G7 based predictions will result in better centered groups on average. Remember, drop 'observations' are subject to all kinds of potential error which I won't list here. It's no surprise that one method doesn't immediately shine over another when there's so much uncertainty with everything else. In other words, the 'signal to noise' ratio is low. But there is a signal, and that signal is that G7 based trajectories are better, even if it's difficult to resolve amongst the static in the environment.
The problem with Pejsa based programs is that no two programmers write them the same way. Especially around transonic, those solvers are all unique to their creators. That flexibility is a good thing if you're writing a program for yourself, or you're trying to match a particular set of radar data. It even makes very strong believers out of people who see the comparison. The flexibility of the pejsa solver becomes a problem when you consider that none of these programs respond the same way to inputs. None of them interpret BC the same way.
The irony is blinding here. The pejsa equations allow the programmer to depart from the G1 curve to something more suitable for LR bullets. So he makes the curve look much more like a G7 curve. But the program still accepts 'G1' BCs, then basically puts it on a G7 curve behind the scenes. The users perception is that "this is a G1 program that gives similar or better results than a G7 program!" It's got the advantage of accepting G1 inputs which makes people 'comfortable', and the smarts to interpret it something like G7.
So why is that a bad thing? The reason it's bad is because not all the pejsa programs do their 'mojo' the same. Some make the curve steeper, some more shallow, some splice their transonic mojo sooner than others, etc etc. All the while, they're all interpreting BC differently than a 'properly written' program which refers to the real G1 or G7 standard. The consequence is that the pejsa based programs will not interpret a BC (G1 or G7) the same as any other program on the planet, even other pejsa programs. So you're forced to tweak them to match your data set.
By contrast, if you're using a conventional point mass solver that refers to an actual standard curve, then that program will agree with any other properly written program when given the same inputs. Why is that valuable? <span style="font-style: italic"><span style="font-weight: bold">Because then the world can agree on what the true BC is for a given bullet</span></span>. Being able to lock down a BC for a bullet is incredibly valuable for many reasons. One is it allows apples-to-apples comparisons between bullets, another reason is that it allows a shooter with no historical data on a bullet to represent it's performance accurately from the get-go, rather than needing to shoot it at many ranges before his program gets 'tuned in'.
If everyone's using their different flavors of half baked pejsa solvers that were tweaked to match different unique data sets, those solvers (all being different) will require different descriptions for the same bullet to get the right answer. Sounds like anarchy to me.
LL provided the perfect example above with his account of the different programs requiring different BC's to arrive at the same correct solution. The program that was written properly (BulletFlight) gave the correct answer when given the correct BC, without needing tweaked at all from the BC I assessed for that bullet. That is a perfect example of how things can work if you use proper solvers and BC's that work together according to how the equations of motion are solved.
The pejsa based programs are all so different and you really do have to tweak them because they don't all interpret BC the same way. It's a problem of standardization, and it's why those programs aren't the best solution if you need a predictive tool. If you just want a tool to tell you what you shot after you already shot it, those tools have the flexibility to do that for you. However if you want the best chance to be on target with a bullet you never fired before, you need a program that will interpret the BC properly, according to the standard, with no mojo, voodoo, or in any way other than how it was intended.
Contrary to popular belief, you don't have to shoot 100's of rounds before you can start being accurate with your ballistic predictions. Marksmanship, yes. Practice at every opportunity. But ballistics is a very mature science that's ready for application from the first shot. Every shooter doesn't have to re-invent the wheel. Just use the right data and tools for the job and focus on shooting. If LL would have done this, he would have been on target from shot #1, using a G7 BC of .243 for the 175 SMK in the right solver.
Granted, it can be difficult for shooters to know which programs are properly written, and apply BC's as intended. Maybe I should make a list.
Rest assured, math didn't take a vacation, and there is no magic involved. We, as shooters, just need to know what to look for.
-Bryan
Re: G1, G7 Ballistics Coeficient?
Bryan- Your Point Mass Program allows only one velocity entry.
Let's say that known 'zeroed' velocity was at 60 degrees, but today is 90 degrees. In the future, will you add a zeroed velocity condition and a current atmospheric condition entry as well?
Thanks.
Bryan- Your Point Mass Program allows only one velocity entry.
Let's say that known 'zeroed' velocity was at 60 degrees, but today is 90 degrees. In the future, will you add a zeroed velocity condition and a current atmospheric condition entry as well?
Thanks.
Re: G1, G7 Ballistics Coeficient?
Lead,
You're talking about temp effects on powder burn rate and MV?
I probably won't put that in my program.
My thinking is that is an internal ballistic effect, and it's an external ballistics calculator (one that I'm trying to keep simple).
I think what you're describing is a good idea, but more so for mobile programs where you'll give it atmoshperics and then need a complete solution. My program is more intended to be an educational desktop tool. For example, if I want to know how much a 20 degree change affects the trajectory (and just the trajectory), it's difficult to isolate the external ballistic effect if the MV is coupled to it.
-Bryan
Lead,
You're talking about temp effects on powder burn rate and MV?
I probably won't put that in my program.
My thinking is that is an internal ballistic effect, and it's an external ballistics calculator (one that I'm trying to keep simple).
I think what you're describing is a good idea, but more so for mobile programs where you'll give it atmoshperics and then need a complete solution. My program is more intended to be an educational desktop tool. For example, if I want to know how much a 20 degree change affects the trajectory (and just the trajectory), it's difficult to isolate the external ballistic effect if the MV is coupled to it.
-Bryan
Re: G1, G7 Ballistics Coeficient?
Bryan,
I hate to say this but you are contradicting yourself, especially in regards to the final output.
You say the pesja solvers are half baked, but using these frequently, they are the best of the bunch... out of the box, with the information provided, sans historical tweaking. And your assertion that it will all change past 600 yards, do you not see the un-tweaked, raw data from LB3 that goes to 1750 yard with a 250gr Scenar, which goes against your logic, is ignoring an important piece of data.
To quote Gus,
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I have said this many times, but one more will not hurt. LB3 ballistics
engine IS NOT PEJSA.
<span style="font-weight: bold">The Doppler data I provided was not tweaked at all.</span> In fact, all the inputs
used are in the article for anyone willing to make its own run and further
comparison,. Tweaking is, in this case, cheating to others and to myself.
</div></div>
So, if this <span style="text-decoration: underline">not tweaked solution</span> can be that close, how is it half baked... ?
I have to qualify, I currently own:
FFS IV
FFS V
FFS Tactical
LB3
Horus ATRAG
BulletFlight
Ballistics
iSnipe
Mil Dot Ballistics
NF ExBal
So to cherry pick out the BulletFlight's tweaked numbers to say if I used .243 I would have been on... but Ballistic claims to use your data, of .252, the original Bulletflight data is listed from the "Bryan Litz Library" as <span style="font-style: italic">hidden</span>, <span style="text-decoration: underline"> this was also wrong until I tweaked it.</span> Granted Bulletflight was better than Ballistics, but both were better with the original G1 solution than the original G7 <span style="font-weight: bold">to 1000 yards.</span> Once I had that data, inputed into the <span style="font-style: italic">"Calculate BC from Drop"</span> utility, it gave me the .243, then for the rifle with it a MV of 2770fps it gave me .237... small like you said, a few percent, but huge in terms of starting with the .252 versus .237. Ballistics gives the 175gr M118LR G7 as .252, anyone with it can look that up, but your saying .243 is the magic number, but the library is giving you a different number.
Now, if the G7 is giving you better performance in the Point Mass programs yet the Half Baked Pesja solvers are giving you the same performance either way, clearly they are on to something Point Mass is not. To me a properly written program is one that gets me on target more consistently... not one that highlights G7 over G1, which has been working for people for a long time. To claim FFS or LB3 are not properly written yet work every bit as well as anything out, makes no sense.
Honestly, your post is an attack on something "not you" because they do well with any G value, not the one you advocate.
I have to say, I routinely crunch the numbers I observe on my off time using all these programs, and LB3 and FFS are the best of the bunch... half baked or otherwise. BulletFlight is awesome for an apt, but the fact, your "hidden" data needs every bit the tweaking as anything else, doesn't fit your logic.
Bryan,
I hate to say this but you are contradicting yourself, especially in regards to the final output.
You say the pesja solvers are half baked, but using these frequently, they are the best of the bunch... out of the box, with the information provided, sans historical tweaking. And your assertion that it will all change past 600 yards, do you not see the un-tweaked, raw data from LB3 that goes to 1750 yard with a 250gr Scenar, which goes against your logic, is ignoring an important piece of data.
To quote Gus,
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I have said this many times, but one more will not hurt. LB3 ballistics
engine IS NOT PEJSA.
<span style="font-weight: bold">The Doppler data I provided was not tweaked at all.</span> In fact, all the inputs
used are in the article for anyone willing to make its own run and further
comparison,. Tweaking is, in this case, cheating to others and to myself.
</div></div>
So, if this <span style="text-decoration: underline">not tweaked solution</span> can be that close, how is it half baked... ?
I have to qualify, I currently own:
FFS IV
FFS V
FFS Tactical
LB3
Horus ATRAG
BulletFlight
Ballistics
iSnipe
Mil Dot Ballistics
NF ExBal
So to cherry pick out the BulletFlight's tweaked numbers to say if I used .243 I would have been on... but Ballistic claims to use your data, of .252, the original Bulletflight data is listed from the "Bryan Litz Library" as <span style="font-style: italic">hidden</span>, <span style="text-decoration: underline"> this was also wrong until I tweaked it.</span> Granted Bulletflight was better than Ballistics, but both were better with the original G1 solution than the original G7 <span style="font-weight: bold">to 1000 yards.</span> Once I had that data, inputed into the <span style="font-style: italic">"Calculate BC from Drop"</span> utility, it gave me the .243, then for the rifle with it a MV of 2770fps it gave me .237... small like you said, a few percent, but huge in terms of starting with the .252 versus .237. Ballistics gives the 175gr M118LR G7 as .252, anyone with it can look that up, but your saying .243 is the magic number, but the library is giving you a different number.
Now, if the G7 is giving you better performance in the Point Mass programs yet the Half Baked Pesja solvers are giving you the same performance either way, clearly they are on to something Point Mass is not. To me a properly written program is one that gets me on target more consistently... not one that highlights G7 over G1, which has been working for people for a long time. To claim FFS or LB3 are not properly written yet work every bit as well as anything out, makes no sense.
Honestly, your post is an attack on something "not you" because they do well with any G value, not the one you advocate.
I have to say, I routinely crunch the numbers I observe on my off time using all these programs, and LB3 and FFS are the best of the bunch... half baked or otherwise. BulletFlight is awesome for an apt, but the fact, your "hidden" data needs every bit the tweaking as anything else, doesn't fit your logic.
Re: G1, G7 Ballistics Coeficient?
Frank, you're making this too easy.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Bryan,
I hate to say this but you are contradicting yourself, especially in regards to the final output.
You say the pesja solvers are half baked, but using these frequently, they are the best of the bunch... out of the box, with the information provided, sans historical tweaking.</div></div>
They're the best 'out of the box' with G1's because pejsa's math morphs a G1 into something closer to G7. But not all Pejsa solvers do this the same, so when you give it a 'true' BC, you don't really know what you're gonna get. You have to shoot, tweak, repeat until you get the program to repeat what you told it. That's not how predictive modeling is supposed to work.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">And your assertion that it will all change past 600 yards, do you not see the un-tweaked, raw data from LB3 that goes to 1750 yard with a 250gr Scenar, which goes against your logic, is ignoring an important piece of data.
</div></div>
I would be very interested to see how LB3 compared to an entirely different piece of radar data, one not available during the development of the solver.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">
To quote Gus,
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I have said this many times, but one more will not hurt. LB3 ballistics
engine IS NOT PEJSA.
<span style="font-weight: bold">The Doppler data I provided was not tweaked at all.</span> In fact, all the inputs
used are in the article for anyone willing to make its own run and further
comparison,. Tweaking is, in this case, cheating to others and to myself.
</div></div>
So, if this <span style="text-decoration: underline">not tweaked solution</span> can be that close, how is it half baked... ?
</div></div>
No-one's saying the radar data was tweaked, I'm saying the solution has to be tweaked to match it, either by the shooter or by the programmer. Pejsa has no standard curves, just blank equations that you can define and modify however you want. He says it's not Pejsa, what is it then? Modified Pejsa? The fact that there's not another solver like it on the planet means you cannot expect it to work with standard BC's. Beyond that, pejsa solvers also require another input to characterize the drag. Some call it a retard coefficient, or a drag coefficient. How do you know what that's supposed to be? Who's publishing the 'industry standard' BC/drag coefficient pairs for all bullets that are intended to work with pejsas equations? (as an interesting side note, I contacted pejsa years ago when I began testing BC's to see if he would be interested in me characterizing bullets specifically for use in his equations so that such standards could be established just for his solvers. He wasn't interested).
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">
I have to qualify, I currently own:
FFS IV
FFS V
FFS Tactical
LB3
Horus ATRAG
BulletFlight
Ballistics
iSnipe
Mil Dot Ballistics
NF ExBal
So to cherry pick out the BulletFlight's tweaked numbers to say if I used .243 I would have been on... but Ballistic claims to use your data, of .252, the original Bulletflight data is listed from the "Bryan Litz Library" as <span style="font-style: italic">hidden</span>, <span style="text-decoration: underline"> this was also wrong until I tweaked it.</span> Granted Bulletflight was better than Ballistics, but both were better with the original G1 solution than the original G7 <span style="font-weight: bold">to 1000 yards.</span> Once I had that data, inputed into the <span style="font-style: italic">"Calculate BC from Drop"</span> utility, it gave me the .243, then for the rifle with it a MV of 2770fps it gave me .237... small like you said, a few percent, but huge in terms of starting with the .252 versus .237. Ballistics gives the 175gr M118LR G7 as .252, anyone with it can look that up, but your saying .243 is the magic number, but the library is giving you a different number.
</div></div>
This is an issue with Ballistic having an inaccurate G7 BC. If they claim to use my library, and they're assigning .252 to the 175 SMK when I clearly assessed that BC to be .243, then that's a coding error on their part, not the fault of the BC.
It's another example of an inaccuracy that's attributable to something other than the true G7 predicted trajectory. There's no way around it; when you use the right standard inputs (including BC) with compatible standard programs, the results are accurate from the first shot. I can't help it of someone changed the BC in the library to something that's wrong.
We're talking about the equations of motion that describe ballistic flight. They have been known since Newton, and <span style="font-style: italic">when applied properly</span>, they simply work. When a mistake is made which results in the math not being applied correctly, they have error.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Now, if the G7 is giving you better performance in the Point Mass programs yet the Half Baked Pesja solvers are giving you the same performance either way, clearly they are on to something Point Mass is not.</div></div>
As stated above, pejsa equations morph the G1 curve into something like a G7, so they work better with inflated (or high velocity) G1 BC's. Doesn't mean they're doing it 'right', just that it's got a built in, offsetting error. What happens if you use the pejsa solution to predict a trajectory using a BC that's actually accurate for the flight speeds the bullet will encounter? who knows. I don't even care because the next pejsa solution won't do the same thing.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">To me a properly written program is one that gets me on target more consistently... not one that highlights G7 over G1, which has been working for people for a long time. To claim FFS or LB3 are not properly written yet work every bit as well as anything out, makes no sense. </div></div>
To me, a properly written solution is one that gets you on target using industry standard definitions of bullet performance. Not one that requires you to shoot a couple boxes of ammo first so you can tell the program your trajectory at all ranges so it can tell it back to you. In other words, to me a properly written program is <span style="font-style: italic">predictive</span>, not reactive.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Honestly, your post is an attack on something "not you" because they do well with any G value, not the one you advocate.</div></div>
Honestly, it's not. I didn't invent the equations of motion, or G7 BC's, or point mass solvers. I've simply been educated on how these things work, and I'm advocating the <span style="font-style: italic">right</span> way for others. If you can get something else to work for you, that's ok. I won't loose any sleep over it. But stating publicly that there is no difference between the methods is something I will address. Granted the difference can be small and easily masked by other errors. But behind all the static, there is a truth, and the closer we get to that truth, the more holes we put in distant targets without every shooter needing to re-define bullet performance.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I have to say, I routinely crunch the numbers I observe on my off time using all these programs, and LB3 and FFS are the best of the bunch... half baked or otherwise. BulletFlight is awesome for an apt, but the fact, your "hidden" data needs every bit the tweaking as anything else, doesn't fit your logic. </div></div>
The only reason my hidden data would need tweaking is if it's hiding the wrong number (as apparently is the case with Ballistic).
Let's review your facts:
You did some careful drop testing of the 175 SMK and compared the observed performance to that predicted by several programs. Those programs were all tweaked to get them to match your hard data.
In the end, after all the riger-marole, you find that the properly written solver with the accurate G7 BC of .243 work together like hand-in-glove to match your observed trajectory.
Finally (and here's the funny part) you conclude that none of the programs or BC's are any better than the others. In fact, you actually favor the solvers that you had to tweak to match what you shot over the one that could have provided the right solution all along if you'd given it the right inputs to begin with (including a BC that was right all along). If this summary of <span style="font-style: italic">your own results</span> doesn't make <span style="font-style: italic">my point</span> crystal clear, I don't know what will.
Just the value in standardization (which doesn't exist for pejsa solvers) is tremendous. Let's say someone pops into the forums asking about the performance of the 175 SMK. The G1 answer is:
Well, Sierra says .505 for 2800 fps+, .496 between 1800 fps and 2800 fps, and .485 below 1800 fps. Or you could just use the average of .495.
Another shooter who shoots that bullet in a .300 Win Mag to 600 yards will swear the average BC is higher than that, while a shooter who routinely shoots a .308 to subsonic will say the average is much lower. A shooter using a pejsa solver will say, well I don't know what number they would give, but it would be a BC'ish number, along with a drag coefficient that is either a default value, or is a number they derived from their own shooting which is of unknown credibility.
So the poor guy who asked the question goes away shaking his head with a vague idea of what to do.
The G7 answer is: .243, period. And that BC will work when used with a proper solver and when all the other inputs are right. You've seen it yourself.
Further to the advantages of G7 BC's; consider the static solvers provided for 'standard' ammo types like the FDAC and the whiz wheel. If part of your process with ballistic calculators is to tweak the numbers till it matches, how do you do that when it's printed? You stated the FDAC is accurate and matches your data. I'm sure you know the FDAC solution for the M118LR/175SMK uses a G7 BC of .243. And it works. And you don't have to 'tweak' it (how would you anyway?) It has to be as 'right' as possible without tweaking, and the best way to achieve this is to use standard definitions of BC, etc.
You're always advocating the practice of marksmanship fundamentals, and consider many ballistic 'phenomena' to be extraneous distractions to shooting. That seems to run counter with your 10 mobile ballistics solvers and your practice of tweaking them all the time. Imagine how much simpler life would be if you just knew the 'right' one(s) to use, and could recommend it to others so they don't waste their time being distracted by fiddling with their programs and were instead out shooting.
It's getting late and I think you've driven my point home with your observations. It's still puzzling how you can make the conclusions you did based on how well you've seen it work, but hey, maybe that's just how you roll.
-Bryan
Frank, you're making this too easy.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Bryan,
I hate to say this but you are contradicting yourself, especially in regards to the final output.
You say the pesja solvers are half baked, but using these frequently, they are the best of the bunch... out of the box, with the information provided, sans historical tweaking.</div></div>
They're the best 'out of the box' with G1's because pejsa's math morphs a G1 into something closer to G7. But not all Pejsa solvers do this the same, so when you give it a 'true' BC, you don't really know what you're gonna get. You have to shoot, tweak, repeat until you get the program to repeat what you told it. That's not how predictive modeling is supposed to work.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">And your assertion that it will all change past 600 yards, do you not see the un-tweaked, raw data from LB3 that goes to 1750 yard with a 250gr Scenar, which goes against your logic, is ignoring an important piece of data.
</div></div>
I would be very interested to see how LB3 compared to an entirely different piece of radar data, one not available during the development of the solver.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">
To quote Gus,
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I have said this many times, but one more will not hurt. LB3 ballistics
engine IS NOT PEJSA.
<span style="font-weight: bold">The Doppler data I provided was not tweaked at all.</span> In fact, all the inputs
used are in the article for anyone willing to make its own run and further
comparison,. Tweaking is, in this case, cheating to others and to myself.
</div></div>
So, if this <span style="text-decoration: underline">not tweaked solution</span> can be that close, how is it half baked... ?
</div></div>
No-one's saying the radar data was tweaked, I'm saying the solution has to be tweaked to match it, either by the shooter or by the programmer. Pejsa has no standard curves, just blank equations that you can define and modify however you want. He says it's not Pejsa, what is it then? Modified Pejsa? The fact that there's not another solver like it on the planet means you cannot expect it to work with standard BC's. Beyond that, pejsa solvers also require another input to characterize the drag. Some call it a retard coefficient, or a drag coefficient. How do you know what that's supposed to be? Who's publishing the 'industry standard' BC/drag coefficient pairs for all bullets that are intended to work with pejsas equations? (as an interesting side note, I contacted pejsa years ago when I began testing BC's to see if he would be interested in me characterizing bullets specifically for use in his equations so that such standards could be established just for his solvers. He wasn't interested).
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">
I have to qualify, I currently own:
FFS IV
FFS V
FFS Tactical
LB3
Horus ATRAG
BulletFlight
Ballistics
iSnipe
Mil Dot Ballistics
NF ExBal
So to cherry pick out the BulletFlight's tweaked numbers to say if I used .243 I would have been on... but Ballistic claims to use your data, of .252, the original Bulletflight data is listed from the "Bryan Litz Library" as <span style="font-style: italic">hidden</span>, <span style="text-decoration: underline"> this was also wrong until I tweaked it.</span> Granted Bulletflight was better than Ballistics, but both were better with the original G1 solution than the original G7 <span style="font-weight: bold">to 1000 yards.</span> Once I had that data, inputed into the <span style="font-style: italic">"Calculate BC from Drop"</span> utility, it gave me the .243, then for the rifle with it a MV of 2770fps it gave me .237... small like you said, a few percent, but huge in terms of starting with the .252 versus .237. Ballistics gives the 175gr M118LR G7 as .252, anyone with it can look that up, but your saying .243 is the magic number, but the library is giving you a different number.
</div></div>
This is an issue with Ballistic having an inaccurate G7 BC. If they claim to use my library, and they're assigning .252 to the 175 SMK when I clearly assessed that BC to be .243, then that's a coding error on their part, not the fault of the BC.
It's another example of an inaccuracy that's attributable to something other than the true G7 predicted trajectory. There's no way around it; when you use the right standard inputs (including BC) with compatible standard programs, the results are accurate from the first shot. I can't help it of someone changed the BC in the library to something that's wrong.
We're talking about the equations of motion that describe ballistic flight. They have been known since Newton, and <span style="font-style: italic">when applied properly</span>, they simply work. When a mistake is made which results in the math not being applied correctly, they have error.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Now, if the G7 is giving you better performance in the Point Mass programs yet the Half Baked Pesja solvers are giving you the same performance either way, clearly they are on to something Point Mass is not.</div></div>
As stated above, pejsa equations morph the G1 curve into something like a G7, so they work better with inflated (or high velocity) G1 BC's. Doesn't mean they're doing it 'right', just that it's got a built in, offsetting error. What happens if you use the pejsa solution to predict a trajectory using a BC that's actually accurate for the flight speeds the bullet will encounter? who knows. I don't even care because the next pejsa solution won't do the same thing.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">To me a properly written program is one that gets me on target more consistently... not one that highlights G7 over G1, which has been working for people for a long time. To claim FFS or LB3 are not properly written yet work every bit as well as anything out, makes no sense. </div></div>
To me, a properly written solution is one that gets you on target using industry standard definitions of bullet performance. Not one that requires you to shoot a couple boxes of ammo first so you can tell the program your trajectory at all ranges so it can tell it back to you. In other words, to me a properly written program is <span style="font-style: italic">predictive</span>, not reactive.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Honestly, your post is an attack on something "not you" because they do well with any G value, not the one you advocate.</div></div>
Honestly, it's not. I didn't invent the equations of motion, or G7 BC's, or point mass solvers. I've simply been educated on how these things work, and I'm advocating the <span style="font-style: italic">right</span> way for others. If you can get something else to work for you, that's ok. I won't loose any sleep over it. But stating publicly that there is no difference between the methods is something I will address. Granted the difference can be small and easily masked by other errors. But behind all the static, there is a truth, and the closer we get to that truth, the more holes we put in distant targets without every shooter needing to re-define bullet performance.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I have to say, I routinely crunch the numbers I observe on my off time using all these programs, and LB3 and FFS are the best of the bunch... half baked or otherwise. BulletFlight is awesome for an apt, but the fact, your "hidden" data needs every bit the tweaking as anything else, doesn't fit your logic. </div></div>
The only reason my hidden data would need tweaking is if it's hiding the wrong number (as apparently is the case with Ballistic).
Let's review your facts:
You did some careful drop testing of the 175 SMK and compared the observed performance to that predicted by several programs. Those programs were all tweaked to get them to match your hard data.
In the end, after all the riger-marole, you find that the properly written solver with the accurate G7 BC of .243 work together like hand-in-glove to match your observed trajectory.
Finally (and here's the funny part) you conclude that none of the programs or BC's are any better than the others. In fact, you actually favor the solvers that you had to tweak to match what you shot over the one that could have provided the right solution all along if you'd given it the right inputs to begin with (including a BC that was right all along). If this summary of <span style="font-style: italic">your own results</span> doesn't make <span style="font-style: italic">my point</span> crystal clear, I don't know what will.
Just the value in standardization (which doesn't exist for pejsa solvers) is tremendous. Let's say someone pops into the forums asking about the performance of the 175 SMK. The G1 answer is:
Well, Sierra says .505 for 2800 fps+, .496 between 1800 fps and 2800 fps, and .485 below 1800 fps. Or you could just use the average of .495.
Another shooter who shoots that bullet in a .300 Win Mag to 600 yards will swear the average BC is higher than that, while a shooter who routinely shoots a .308 to subsonic will say the average is much lower. A shooter using a pejsa solver will say, well I don't know what number they would give, but it would be a BC'ish number, along with a drag coefficient that is either a default value, or is a number they derived from their own shooting which is of unknown credibility.
So the poor guy who asked the question goes away shaking his head with a vague idea of what to do.
The G7 answer is: .243, period. And that BC will work when used with a proper solver and when all the other inputs are right. You've seen it yourself.
Further to the advantages of G7 BC's; consider the static solvers provided for 'standard' ammo types like the FDAC and the whiz wheel. If part of your process with ballistic calculators is to tweak the numbers till it matches, how do you do that when it's printed? You stated the FDAC is accurate and matches your data. I'm sure you know the FDAC solution for the M118LR/175SMK uses a G7 BC of .243. And it works. And you don't have to 'tweak' it (how would you anyway?) It has to be as 'right' as possible without tweaking, and the best way to achieve this is to use standard definitions of BC, etc.
You're always advocating the practice of marksmanship fundamentals, and consider many ballistic 'phenomena' to be extraneous distractions to shooting. That seems to run counter with your 10 mobile ballistics solvers and your practice of tweaking them all the time. Imagine how much simpler life would be if you just knew the 'right' one(s) to use, and could recommend it to others so they don't waste their time being distracted by fiddling with their programs and were instead out shooting.
It's getting late and I think you've driven my point home with your observations. It's still puzzling how you can make the conclusions you did based on how well you've seen it work, but hey, maybe that's just how you roll.
-Bryan
Re: G1, G7 Ballistics Coeficient?
Bryan,
I understand it is late, but if Ballistics is wrong with .252, and BulletFlight is wrong with the <span style="font-style: italic">Hidden</span> and with one rifle .243 <span style="font-style: italic">(understood and acknowledged to be correct)</span> works with a muzzle velocity in the 2600fps region, but G7 of .237 work at 2770fps, what difference does it make you saying the curve model is better ? According to you it is better, according to both programs, neither is right.
You keep referring to .243 but fail to note I have mentioned .237 more than once, how is that different than .505 versus .496 ? My observations as well as others say it's the same.
<span style="font-weight: bold">Honestly, All I am saying is, you have to tweak them all...</span> both G7 and G1 require it, there is no magic number. The FDAC works provided I put in the right card in, and correct me if I am wrong the "whiz wheel" accounts for "tweaking" as well.
As far as me having 10 mobile program, and me crunching numbers off the line, well I answered that earlier. I have a natural curiosity and I don't take one persons' or devices word for it. I hunt, experiment and see who gives me the best down range results with the least amount of effort. When I flip open Ballistics and its wrong, and see the same thing over and over, and that each program needs tweaking, well then I want to see which programs need the least amount of it. And give me best solutions across multiple rifles or rounds used.
My process is quite simple, I confirm on paper, re-calculate the BC and then move forward. Or you can use the DK function in FFS or LB3... its fairly easy.
However if both Bulletflight and Ballistics are using incorrect G7BL data...
What you are telling everyone is, if you don't carry Applied Ballistics in the field, you have a good chance of being off.
My point specifically is calling good programs <span style="font-weight: bold"> "half baked"</span> when clearly FFS and LB3 are excellent at solving the problem of putting rounds on target. The evidence to that is your words that both Ballistics and Bulletflight have the G7 values wrong ?
And explain why it is "hidden" if you expect people to use it ? Telling people it is right and not giving them number is wrong on a lot of levels.
Sorry you don't like the fact I question this, and I am not blindly following your lead... don't underestimate the fact I question things by thinking I am doing so without trying them first, or for that matter, often. I'm pretty good at knowing this stuff without needing a book in front of me. I empty a lot of brass and not for the sake of dumping rounds on target, I alway have a point to my practice, whether it is the fundamentals I preach or the checking of numbers I am given. There is hardly a week that goes by I am not on the range in some manner.
I use both, G1 and G7, I reference you book often, I utilize technology, none of this is above me or below me. However I also acknowledge results and when things aren't matching up, I want to know why. I don't mean to be combative, but when I see things that are <span style="font-style: italic">caveated, contradictory, and canted,</span> well it calls into question a lot of what I see... it feels sold and not necessarily solid.
Bryan,
I understand it is late, but if Ballistics is wrong with .252, and BulletFlight is wrong with the <span style="font-style: italic">Hidden</span> and with one rifle .243 <span style="font-style: italic">(understood and acknowledged to be correct)</span> works with a muzzle velocity in the 2600fps region, but G7 of .237 work at 2770fps, what difference does it make you saying the curve model is better ? According to you it is better, according to both programs, neither is right.
You keep referring to .243 but fail to note I have mentioned .237 more than once, how is that different than .505 versus .496 ? My observations as well as others say it's the same.
<span style="font-weight: bold">Honestly, All I am saying is, you have to tweak them all...</span> both G7 and G1 require it, there is no magic number. The FDAC works provided I put in the right card in, and correct me if I am wrong the "whiz wheel" accounts for "tweaking" as well.
As far as me having 10 mobile program, and me crunching numbers off the line, well I answered that earlier. I have a natural curiosity and I don't take one persons' or devices word for it. I hunt, experiment and see who gives me the best down range results with the least amount of effort. When I flip open Ballistics and its wrong, and see the same thing over and over, and that each program needs tweaking, well then I want to see which programs need the least amount of it. And give me best solutions across multiple rifles or rounds used.
My process is quite simple, I confirm on paper, re-calculate the BC and then move forward. Or you can use the DK function in FFS or LB3... its fairly easy.
However if both Bulletflight and Ballistics are using incorrect G7BL data...
What you are telling everyone is, if you don't carry Applied Ballistics in the field, you have a good chance of being off.
My point specifically is calling good programs <span style="font-weight: bold"> "half baked"</span> when clearly FFS and LB3 are excellent at solving the problem of putting rounds on target. The evidence to that is your words that both Ballistics and Bulletflight have the G7 values wrong ?
And explain why it is "hidden" if you expect people to use it ? Telling people it is right and not giving them number is wrong on a lot of levels.
Sorry you don't like the fact I question this, and I am not blindly following your lead... don't underestimate the fact I question things by thinking I am doing so without trying them first, or for that matter, often. I'm pretty good at knowing this stuff without needing a book in front of me. I empty a lot of brass and not for the sake of dumping rounds on target, I alway have a point to my practice, whether it is the fundamentals I preach or the checking of numbers I am given. There is hardly a week that goes by I am not on the range in some manner.
I use both, G1 and G7, I reference you book often, I utilize technology, none of this is above me or below me. However I also acknowledge results and when things aren't matching up, I want to know why. I don't mean to be combative, but when I see things that are <span style="font-style: italic">caveated, contradictory, and canted,</span> well it calls into question a lot of what I see... it feels sold and not necessarily solid.
Re: G1, G7 Ballistics Coeficient?
And one after thought,
It doesn't matter what the curve says, the end user has no control over that, they have access to the provided library of bullet data, then they are responsible for inputting their muzzle velocity, barometric pressure, temperature, etc...
How the programs adjusts the information to match the curve is outta our hands, all that matters after is the end result at the target. So if LB3, or FFS are changing the G1 curve to perform like a G7 so what the end result is the same. So to say are they doing it wrong but getting a correct end result , well that is not doing it wrong in my opinion. Shouldn't matter to the user if one program is different from the other, which they already clearly are, what matters is the hit.
Programs, data sheets, the lot have been out there for a long time before the G7 BCs became available, people hit their targets fine, so the idea these solutions are half baked or otherwise doesn't pass the test.
This is why it's no different, because if they can repeatedly and successfully manipulate the curve or have the program utilize the history of the curve to model a prediction that results in a hit, then it's a win for everyone. And if banded BCs work better with multiple muzzle velocities that is the one people will use especially if that is more widely available at their finger tips. I would rather input .505 on down from 2800 to 1800 then have to guess what they were using under the hood of hidden.
And one after thought,
It doesn't matter what the curve says, the end user has no control over that, they have access to the provided library of bullet data, then they are responsible for inputting their muzzle velocity, barometric pressure, temperature, etc...
How the programs adjusts the information to match the curve is outta our hands, all that matters after is the end result at the target. So if LB3, or FFS are changing the G1 curve to perform like a G7 so what the end result is the same. So to say are they doing it wrong but getting a correct end result , well that is not doing it wrong in my opinion. Shouldn't matter to the user if one program is different from the other, which they already clearly are, what matters is the hit.
Programs, data sheets, the lot have been out there for a long time before the G7 BCs became available, people hit their targets fine, so the idea these solutions are half baked or otherwise doesn't pass the test.
This is why it's no different, because if they can repeatedly and successfully manipulate the curve or have the program utilize the history of the curve to model a prediction that results in a hit, then it's a win for everyone. And if banded BCs work better with multiple muzzle velocities that is the one people will use especially if that is more widely available at their finger tips. I would rather input .505 on down from 2800 to 1800 then have to guess what they were using under the hood of hidden.
Re: G1, G7 Ballistics Coeficient?
To me you are a statistician (i'll compute, i'll estimate or i'll do a voodoo magic whatever it takes to get a result) and Bryan is a mathematician (i'll rather die than take a guess and no result is better than result based on "guess"). There has been a long history of conflict between those two branches and you two won't solve a thing in this area
. While mathematicians allow for no error no matter what statisticians will accept a predetermined amount of error and get some usable solution.
Fact is G7 model more accurately fits the modern bullet line of flight however fact also is that G7 is NOT the standard or NOT even necessary to get usable result for most applications. I don't mind if G7 becomes the standard nor do I mind if bullets are marketed with G1 BC. I usually do not launch ballistics missiles (or build them) so i could care less about pinpoint accuracy in longer ranges and as its proven firing solutions for most bullets can be obtained with little fuss (its easier to get correct result with G7 for an unknown bullet however what we're shooting with is usually well known and researched).
To me you are a statistician (i'll compute, i'll estimate or i'll do a voodoo magic whatever it takes to get a result) and Bryan is a mathematician (i'll rather die than take a guess and no result is better than result based on "guess"). There has been a long history of conflict between those two branches and you two won't solve a thing in this area
Fact is G7 model more accurately fits the modern bullet line of flight however fact also is that G7 is NOT the standard or NOT even necessary to get usable result for most applications. I don't mind if G7 becomes the standard nor do I mind if bullets are marketed with G1 BC. I usually do not launch ballistics missiles (or build them) so i could care less about pinpoint accuracy in longer ranges and as its proven firing solutions for most bullets can be obtained with little fuss (its easier to get correct result with G7 for an unknown bullet however what we're shooting with is usually well known and researched).
Re: G1, G7 Ballistics Coeficient?
Frank,
It seems like you're continuing to repeat the same things. So I'll state my position once more as well, then we can call a truce/stalemate.
<span style="font-style: italic">When you input the correct G7 BC in a program that used it properly according to industry standards, they produced a perfect trajectory prediction.</span> Any other combination of solvers and BC's needed tweaked to converge on the right answer.
You haven't seemed to contradict the above facts in any of your posts, and to me it's the important conclusion to take from this discussion.
-Bryan
Frank,
It seems like you're continuing to repeat the same things. So I'll state my position once more as well, then we can call a truce/stalemate.
<span style="font-style: italic">When you input the correct G7 BC in a program that used it properly according to industry standards, they produced a perfect trajectory prediction.</span> Any other combination of solvers and BC's needed tweaked to converge on the right answer.
You haven't seemed to contradict the above facts in any of your posts, and to me it's the important conclusion to take from this discussion.
-Bryan
Re: G1, G7 Ballistics Coeficient?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">When you input the correct G7 BC in a program that used it properly according to industry standards, they produced a perfect trajectory prediction. Any other combination of solvers and BC's needed tweaked to converge on the right answer.</div></div>
That <span style="font-style: italic">may</span> be true if each individual shot is at precisely the velocity which the program is given. Alas, that's rarely the case - and then there are all the other variables which can effect a given shot, already enumerated elsewhere.
Given that there is no way to precisely specify the value of some of those variables prior to the shot, I'm afraid that the search for the perfect prediction will continue - in vain.
Now, an imperfect prediction is better than a bad prediction, or none. My experience in life has been that perfection is a goal which is worthwhile to pursue, even without the expectation that it can be achieved. Errors can not be eliminated, but they can be reduced.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">When you input the correct G7 BC in a program that used it properly according to industry standards, they produced a perfect trajectory prediction. Any other combination of solvers and BC's needed tweaked to converge on the right answer.</div></div>
That <span style="font-style: italic">may</span> be true if each individual shot is at precisely the velocity which the program is given. Alas, that's rarely the case - and then there are all the other variables which can effect a given shot, already enumerated elsewhere.
Given that there is no way to precisely specify the value of some of those variables prior to the shot, I'm afraid that the search for the perfect prediction will continue - in vain.
Now, an imperfect prediction is better than a bad prediction, or none. My experience in life has been that perfection is a goal which is worthwhile to pursue, even without the expectation that it can be achieved. Errors can not be eliminated, but they can be reduced.
