Has anyone done any testing to determine bullet strike deviation per powder deviation. I appreciate opinions, but I would really like to hear from the guy that ran some tests? I'm also currious to know if anyone has experienced the perfect powder thrower and if so, what is it?
- Thread starter freeway
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Re: small powder deviations a big deal?
Powder throwing can be heavily influenced by the form used to operate... ie operator error can form part of bad throwing.
That being said, a powder thrower isnt generally the final stop determining the accuracy of the load... it usually extends to a powder trickler on a balance beam.
And to answer your question about the deviation, that also depends on the deviation of your charge from its optimal charge.
For example say your rifle has an accuracy node at 50.0grains on a given powder. At 50.1, or 49.9 gr you may still find that it shoots well, even very well at short distances from 200-300 yards. Whereas if you deviate half a grain your groups may suddenly open up a lot.
The deviation generally occurs in the vertical plane, with horizontal bullet deviation generally resulting from wind.
If your starting out I would recomend getting a decent powder thrower, balance beam and a powder tricklet. Set up the equipment properly and learn how to use it.
Powder throwing can be heavily influenced by the form used to operate... ie operator error can form part of bad throwing.
That being said, a powder thrower isnt generally the final stop determining the accuracy of the load... it usually extends to a powder trickler on a balance beam.
And to answer your question about the deviation, that also depends on the deviation of your charge from its optimal charge.
For example say your rifle has an accuracy node at 50.0grains on a given powder. At 50.1, or 49.9 gr you may still find that it shoots well, even very well at short distances from 200-300 yards. Whereas if you deviate half a grain your groups may suddenly open up a lot.
The deviation generally occurs in the vertical plane, with horizontal bullet deviation generally resulting from wind.
If your starting out I would recomend getting a decent powder thrower, balance beam and a powder tricklet. Set up the equipment properly and learn how to use it.
Re: small powder deviations a big deal?
Being off .1 grain of powder is very bad. It isn't likely to harm accuracy but it might make your rear sling swivel stud rust.
How much speed variation occurs with a .1 gr. change sorta varies by cartridge size, bullet weight, powder type and the pressure/speed it's loaded to. So it's not very well calibrated, you know? And the inconsistancy will remain consistant no matter how well someone tests it.
A measure is a measure. As said above, it's the operator that makes for consistancy, or the lack of it. And coarse powders are just hard to measure consistantly no matter how we do it. Then the trickler comes into play.
Being off .1 grain of powder is very bad. It isn't likely to harm accuracy but it might make your rear sling swivel stud rust.
How much speed variation occurs with a .1 gr. change sorta varies by cartridge size, bullet weight, powder type and the pressure/speed it's loaded to. So it's not very well calibrated, you know? And the inconsistancy will remain consistant no matter how well someone tests it.
A measure is a measure. As said above, it's the operator that makes for consistancy, or the lack of it. And coarse powders are just hard to measure consistantly no matter how we do it. Then the trickler comes into play.
Re: small powder deviations a big deal?
Are you shooting rifle or pistol? If you are shooting rifle google OCW or Optimal Charge Weight and bone up on how to perform a ladder test.
The OCW method works and because you determine a charge range it takes a lot of variation out of your handloads. When I do load development I start with a scale but generally end up being able to use the Lee Dipper Cups with great accuracy and repeatability in my handloads.
Are you shooting rifle or pistol? If you are shooting rifle google OCW or Optimal Charge Weight and bone up on how to perform a ladder test.
The OCW method works and because you determine a charge range it takes a lot of variation out of your handloads. When I do load development I start with a scale but generally end up being able to use the Lee Dipper Cups with great accuracy and repeatability in my handloads.
Re: small powder deviations a big deal?
Did some testing with my .308 several years ago.
I load 42.8 R-15 pushing a 175 Gn. SMK.
.1 Gn. either side of thet load will open my group up at 100 Yds. by 1/4 to 3/8 of an inch which at 1000 yards that amount is an increased by a factor of 10.
1/4"=2.5"
3/8"=3.75"
With all the other exterrior factors to contend with at 1000 everything you can eliminate is important.
Did some testing with my .308 several years ago.
I load 42.8 R-15 pushing a 175 Gn. SMK.
.1 Gn. either side of thet load will open my group up at 100 Yds. by 1/4 to 3/8 of an inch which at 1000 yards that amount is an increased by a factor of 10.
1/4"=2.5"
3/8"=3.75"
With all the other exterrior factors to contend with at 1000 everything you can eliminate is important.
Re: small powder deviations a big deal?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: freeway</div><div class="ubbcode-body">Has anyone done any testing to determine bullet strike deviation per powder deviation. </div></div>
There is an Optimal Charge Weigth (OCW) technique to find an accuracy node that is maximally insensitive to CW variations. The final step in this process is to make ammo with as fine a step size as you cn muster and use this set of loadings to identify how wide the CW window is. For my particular load, and mu gun <add other caveats> the window is 0.25 gr wide. That is all CW between 47.68 and 47.83 shoot like the dickens.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> I'm also currious to know if anyone has experienced the perfect powder thrower and if so, what is it? </div></div>
I like my 30BR but I can tell you that no thrower will throw stick powders to the required accuracy if you are looking for 0.25" groups; 0.5" groups--sure. I throw, measure and trickle.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: freeway</div><div class="ubbcode-body">Has anyone done any testing to determine bullet strike deviation per powder deviation. </div></div>
There is an Optimal Charge Weigth (OCW) technique to find an accuracy node that is maximally insensitive to CW variations. The final step in this process is to make ammo with as fine a step size as you cn muster and use this set of loadings to identify how wide the CW window is. For my particular load, and mu gun <add other caveats> the window is 0.25 gr wide. That is all CW between 47.68 and 47.83 shoot like the dickens.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> I'm also currious to know if anyone has experienced the perfect powder thrower and if so, what is it? </div></div>
I like my 30BR but I can tell you that no thrower will throw stick powders to the required accuracy if you are looking for 0.25" groups; 0.5" groups--sure. I throw, measure and trickle.
Re: small powder deviations a big deal?
I've done some pretty serious testing on this subject because I realized that my CM1500 didn't register a difference when I added or subtracted a few sticks of Varget.
So I set out to test the difference between 44.4gr dead even on a beam scale and on the CM1500 and 44.4gr on the CM1500 and high on a beam scale but not 44.5gr.
I shot a ton of these to make for a statistically actuate test and really found no difference.
However, there may have been a difference but the diameter of the bullet could have hidden the difference.
I've done some pretty serious testing on this subject because I realized that my CM1500 didn't register a difference when I added or subtracted a few sticks of Varget.
So I set out to test the difference between 44.4gr dead even on a beam scale and on the CM1500 and 44.4gr on the CM1500 and high on a beam scale but not 44.5gr.
I shot a ton of these to make for a statistically actuate test and really found no difference.
However, there may have been a difference but the diameter of the bullet could have hidden the difference.
Re: small powder deviations a big deal?
I would like to also add to this that different powders can have a vastly different effect as well.
If australia we have ADI Powders that have a different code to what you guys in the states are used to seeing.
AR2208 - Varget Equivalent -
AR2206H - No idea what its Equivalent to -
Both of these powders are suitable for use in a .308win, however out of the two powders the AR2208 (Varget) seems to be the most forgiving. A small deviation in powder makes little difference in comparison to a small deviation when using AR2206H.
Then again to some people "little difference" may mean a big difference.
Burn rate of the powder will have an influence on the effect
I would like to also add to this that different powders can have a vastly different effect as well.
If australia we have ADI Powders that have a different code to what you guys in the states are used to seeing.
AR2208 - Varget Equivalent -
AR2206H - No idea what its Equivalent to -
Both of these powders are suitable for use in a .308win, however out of the two powders the AR2208 (Varget) seems to be the most forgiving. A small deviation in powder makes little difference in comparison to a small deviation when using AR2206H.
Then again to some people "little difference" may mean a big difference.
Burn rate of the powder will have an influence on the effect
Re: small powder deviations a big deal?
i talked to a Sierra ballistician. He pulled a bunch of match ammo and found the variation in charges to be large.He didn't say exactly how large. I pulled a bunch of green tip 556 and found the charges on 8 rounds to vary +/- .5 grains. My Dillon electronic scale advertises 0.1 grain accuracy. I'd suggest you'd never notice +/- .1 gr variation, even if you could measure it. .1 gr is about, what, 4 flakes of Varget?
i talked to a Sierra ballistician. He pulled a bunch of match ammo and found the variation in charges to be large.He didn't say exactly how large. I pulled a bunch of green tip 556 and found the charges on 8 rounds to vary +/- .5 grains. My Dillon electronic scale advertises 0.1 grain accuracy. I'd suggest you'd never notice +/- .1 gr variation, even if you could measure it. .1 gr is about, what, 4 flakes of Varget?
Re: small powder deviations a big deal?
They pump out factory ammo at an amazing rate, in order to produce ammo within 0.1 of grain powder variation, the rate of production would slow down considerably i would think
They pump out factory ammo at an amazing rate, in order to produce ammo within 0.1 of grain powder variation, the rate of production would slow down considerably i would think
Re: small powder deviations a big deal?
From 1993
http://groups.google.com/group/rec.guns/...e196b706ddefc6f
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">..top shooters in the `other most accuracy-demanding shooting sport'
do weigh powder charges to +/- one tenth of a grain. This is highpower competition where a 20 fps velocity spread means 8 inches (eight tenths MOA) vertical stringing at 1000 yards using a .308 Win.</div></div>
From 1993
http://groups.google.com/group/rec.guns/...e196b706ddefc6f
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">..top shooters in the `other most accuracy-demanding shooting sport'
do weigh powder charges to +/- one tenth of a grain. This is highpower competition where a 20 fps velocity spread means 8 inches (eight tenths MOA) vertical stringing at 1000 yards using a .308 Win.</div></div>
Re: small powder deviations a big deal?
You guys should pay more attention to flashhole & MitchAlsup and their statements about using the OCW method and quit looking for solutions when you have it in front of you.
It WORKS.
How do you think Federal can load thousands of rounds on automated machinery that will shoot into less than 1/2 MOA in a good rifle, using Federal brass, of all things?
Lot to lot, day to day, year to year.....it ALL shoots great in MOST rifles, not one rifle we carefully worked up a load for, like we're talking about struggling with here. Any idea how they accomplish this miracle?
Easy; <span style="text-decoration: underline">they are working in the OCW range of charge weights</span> and tiny (normal) variations don't yield the kind of deviation one would normally expect.
If your load is so sensitive to variation that you have to weigh your charges to a tenth to maintain (field) accuracy, you load is clearly not stable. In fact, most benchrest shooters THROW charges, and while they do get extremely consistent results, they're not throwing them 1/10th apart.
My last load development took 15 rounds, and I'm still using the same charge 1,200 rounds later.
http://optimalchargeweight.embarqspace.com/
You guys should pay more attention to flashhole & MitchAlsup and their statements about using the OCW method and quit looking for solutions when you have it in front of you.
It WORKS.
How do you think Federal can load thousands of rounds on automated machinery that will shoot into less than 1/2 MOA in a good rifle, using Federal brass, of all things?
Lot to lot, day to day, year to year.....it ALL shoots great in MOST rifles, not one rifle we carefully worked up a load for, like we're talking about struggling with here. Any idea how they accomplish this miracle?
Easy; <span style="text-decoration: underline">they are working in the OCW range of charge weights</span> and tiny (normal) variations don't yield the kind of deviation one would normally expect.
If your load is so sensitive to variation that you have to weigh your charges to a tenth to maintain (field) accuracy, you load is clearly not stable. In fact, most benchrest shooters THROW charges, and while they do get extremely consistent results, they're not throwing them 1/10th apart.
My last load development took 15 rounds, and I'm still using the same charge 1,200 rounds later.
http://optimalchargeweight.embarqspace.com/
Re: small powder deviations a big deal?
Correction: most *point blank* benchrest shooters throw charges. You'd be looking long and hard to find a long range (600-1000yd) BR shooter that doesn't weigh charges.
Correction: most *point blank* benchrest shooters throw charges. You'd be looking long and hard to find a long range (600-1000yd) BR shooter that doesn't weigh charges.
Re: small powder deviations a big deal?
I don't know about that, I was at our club range the other day, they are having a sanctioned BR match there this weekend, the BR boys were making fun of my rifle, anyway I watched as they loaded and shot, one guy was throwing charges, the rest had vials of powder they dumbed in each case, they pre measure loads and store in the vials
I don't know about that, I was at our club range the other day, they are having a sanctioned BR match there this weekend, the BR boys were making fun of my rifle, anyway I watched as they loaded and shot, one guy was throwing charges, the rest had vials of powder they dumbed in each case, they pre measure loads and store in the vials
Re: small powder deviations a big deal?
It would be interesting to find out if the charges that were in the vials were thrown, or trickled.
It would be interesting to find out if the charges that were in the vials were thrown, or trickled.
Re: small powder deviations a big deal?
I'd almost bet money those in vials are weighed. Oddly enough, following along various threads over @ Benchrest Central, more of the point-blank crowd is moving to weighed charges (battery packs for their Chargemasters to load at the range, etc.) Not a wholesale move, by any means, but its starting
I'd almost bet money those in vials are weighed. Oddly enough, following along various threads over @ Benchrest Central, more of the point-blank crowd is moving to weighed charges (battery packs for their Chargemasters to load at the range, etc.) Not a wholesale move, by any means, but its starting
Re: small powder deviations a big deal?
Most benchrest shooters use a high end manual powder measure and throw by hand. Out to 300 yards I do that with my Harrell's Premium. Longer range match loads get weighed.
Most benchrest shooters use a high end manual powder measure and throw by hand. Out to 300 yards I do that with my Harrell's Premium. Longer range match loads get weighed.
Re: small powder deviations a big deal?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: memilanuk</div><div class="ubbcode-body">Correction: most *point blank* benchrest shooters throw charges. You'd be looking long and hard to find a long range (600-1000yd) BR shooter that doesn't weigh charges. </div></div>True, sorry for the ambiguity.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: memilanuk</div><div class="ubbcode-body">Correction: most *point blank* benchrest shooters throw charges. You'd be looking long and hard to find a long range (600-1000yd) BR shooter that doesn't weigh charges. </div></div>True, sorry for the ambiguity.
