kestrel in G1 or G7 (as if I know what that means)

[H_Talon]

educate me on the applied ballistics G1 - G2

my calibers are

358win, 7mm-08, 300sav, 30-06, 223, 5.56mm,
358Hawk, to name a few .. for the most part I'll use
the 7mm-08 for long range tac matches.

please be gentle

thanks !!!

 

[Ring]

Re: kestrel in G1 or G7 (as if I know what that means)

the new "shooter" kestrel is g7 for all G7 litz data, but you can youe g1 if u need it... the horis kestrel is g1 i believe..

the 358 you wont find factory g7 that i know of, you "can" convert g1 to g7...

the others, much g7 is out there... but its bullet specific..

 

[noeesp]

Re: kestrel in G1 or G7 (as if I know what that means)

I am really confused

 

[roggom]

Re: kestrel in G1 or G7 (as if I know what that means)

^^ get Bryan's book http://www.appliedballisticsllc.com/index_files/Book.htm

Here is a quick rundown: http://www.calguns.net/calgunforum/showthread.php?t=283567

Bryan stops by on the site once in a while and I am sure if you have a specific question he usually answers them. To truly get an in depth understanding you will have to do some reading.

 

[Laseredge]

Re: kestrel in G1 or G7 (as if I know what that means)

G1 is a more complicated algorithm than G7.

G1 is like having a baseline of a stock Honda Civic doing a .25 mile drag race and then coming up with an algorithm to model a Maserati based upon that data.

G7 uses a Ferrari for the baseline, and then models the Maserati upon it.

Since we are shooting high BC boat tail bullets we use a baseline that is closer to what we are modeling (G7).

I read Applied Ballistics.
I recommend using G7, as much as possible.

 

[Redmanss]

Re: kestrel in G1 or G7 (as if I know what that means)

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2398788

 

[Lowlight]

Re: kestrel in G1 or G7 (as if I know what that means)

If you are using a piece of software that uses Point Mass, like the Kestrel uses, it is easier to use G7, as the software is biased against G1. Point Mass Solvers handle the G Factor in a different way, it likes G7 over G1. (unless adjusted)

if you use Software that is not G Factor Biased like Field Firing Solutions or ColdBore 1.0 you can use either. (In fact FFS does not even use G7 because it doesn't have too) These handle both equally, as noted below when compared to Doppler:

Apps and software from Applied Ballistics tend to work better with G7, however they still need to be adjusted for the shooter and rifle the same way. You get no free lunch with either. Bryan just does a much better job of doing the work for you, so using his data, usually the numbers are pretty solid. However his data is limited.

G1 has been around since the beginning and has been adjusted for modern bullets, it's proven, available and works very well. Especially when you band it. G7 is newer and has limited data available and will also work better if banded, but that is not always as necessary. We have well used averages with G1 and people are starting to see adjusted averages in G7 also. As long as you know the difference, like using .496 for a 175SMK instead of .505 you are good.

It's basically describing the bullet shape and how it will fly on the ballistic curve when modeled via the software. Not all software models it the same.

 

[H_Talon]

Re: kestrel in G1 or G7 (as if I know what that means)


Lowlight you said ..

"Especially when you band it"

if I may ask ,,, what is banding ??

thanks for all the information guys, still
working on what it means

 

[Christopher Rance]

Re: kestrel in G1 or G7 (as if I know what that means)

I disagree on using the Inflated G1 BC's that are advertised. I have had to use G1 BC's but I reference Litz's experimental BC data. For an example the 175 SMK BC G1 avg is .475 I have had tremendous success with that number.

In regard to banding BC's, unless I'm shooting through transonic and into subsonic I just stick with the one average BC.

If the majority of my shooting is inside the supersonic flight of the bullet, ill true at Transonic LE and adjust MV to match real world data.

Again though Im no expert and I would like to learn more on how coldbore and FFS work compared to the point mass ballistic solvers.

 

[Lowlight]

Re: kestrel in G1 or G7 (as if I know what that means)

Of course advertised BCs are inflated, (it's how they sell a bullet) they are usually based on a higher MV, again, going with 175SMK example, the .505 advertised number is based off 3000fps. We don't shoot them at 3000fps. The .496 has been well used for years, and that handles most rifles with a MV over 2650fps very well, if your MV is less then that, a lower average probably works.

BCs are fluid because they are based off your rifle and MV, what I say for me, may not be the same for you because our rifles are different. The end result will vary, we use these "averages" as a starting point and not a finishing one.

Examples of banding both G1 or G7 can be found in a number of places, and this helps "adjust the curve" on the fly giving the software a better picture of the bullet's flight to use.

Go to JBM Software online for free, select the 175SMK with G1 and you can see an example of banding.

From a MV of 2800 to 5000 it shows .505
From a MV of 1800 to 2800 it shows .496
From a MV of 0 to 1800 it shows .485

This is an example of banding your BC, this is how the computer is figuring your solution. You can actually do it with anything and it works out well. And the computer does this automatically with G1 for you, no extra steps.

If you are "tweaking" your MV, either you are not chronographing or your BC is wrong, sure the chronograph can be off... but then again, if you are tweaking with any G Factor you are doing the exact same amount of work and can probably get the exact same answer out of G1 or G7. What is the difference in that case ?

Like I said, G1 has been around for a long time, and continues to be around. Bryan has done very well to match G7 to modern software, which in turn gives people excellent results with them. But the amount of effort can be the same, in the case of G7, you just let Bryan do most of it for you and hope it matches "your Rifle" better than you trying to do it.

But honestly, whether you use .475 vs my .496, or if you use .243 G7 vs me using .239, what is the difference... well us. How my rifle shoots vs your rifle that is the difference. Otherwise it's just a fluid number designed to get you on the right path to success. Someone people tweak the BC, others tweak the MV, we are doing the same thing, bending the curve.

Better program handles the information in better ways, follow that link you can read all about it. Ballistics AE does one thing, Bulletflight does another with the same information so using both together will yield two different results.

MV matters... and advertised BCs are not the end, but the beginning of the process.

 

[noeesp]

Re: kestrel in G1 or G7 (as if I know what that means)

Thanks for clearing that up lowlight

 

[H_Talon]

Re: kestrel in G1 or G7 (as if I know what that means)


thank you Lowlight that helps , now to decide if I need a combo unit or not ..

thanks to all for the help ...