What kind of brass prep do you do for your precision AR15? I've tried the same load in BHA brass without much prep and had much better accuracy with the same load compared to PMC brass with primer pockets uniformed. Do you do any neck turning, flash hole deburring, primer pocket uniforming, sorting by weight, etc?
- Thread starter johngfoster
- Start date
Re: Brass prep for precision AR15
Uniform the primer pockets, Deburr the flash holes. Sort them all for weight.
Check for neck wall run out. Anneal the necks.
I played with neck turning to about 90% clean up and returns in an AR (.223) were negligible @ 1000 yds.
Enjoy.
Uniform the primer pockets, Deburr the flash holes. Sort them all for weight.
Check for neck wall run out. Anneal the necks.
I played with neck turning to about 90% clean up and returns in an AR (.223) were negligible @ 1000 yds.
Enjoy.
Re: Brass prep for precision AR15
I do a quick inspection on Lapua brass and load. FL resize with RCBS small base dies and seat with RCBS standard seater. Powder is thrown with Harrels powder measure. I throw and go. Not shooting past 300 yds at the moment, but it's just as accurate as my full prepped and weighed stuff for a bolt gun. I think brass that is weight sorted will net the biggest gain in accuracy. That is what I have noticed.
Brass is expensive, but once I started to buy/use it I will buy/use nothing else if I have a choice.
I do a quick inspection on Lapua brass and load. FL resize with RCBS small base dies and seat with RCBS standard seater. Powder is thrown with Harrels powder measure. I throw and go. Not shooting past 300 yds at the moment, but it's just as accurate as my full prepped and weighed stuff for a bolt gun. I think brass that is weight sorted will net the biggest gain in accuracy. That is what I have noticed.
Brass is expensive, but once I started to buy/use it I will buy/use nothing else if I have a choice.
Re: Brass prep for precision AR15
1. Trim the cases to uniform length.
2. Anneal the cases (semis are harder on brass).
I've also had some success with using the Lee Factory Crimp die for some of my loads.
1. Trim the cases to uniform length.
2. Anneal the cases (semis are harder on brass).
I've also had some success with using the Lee Factory Crimp die for some of my loads.
Re: Brass prep for precision AR15
Clean, uniform the pockets, deburr, run through possum hollow case trimmer, chamfer inside and outside of case mouth, drop powder with Redding powder dropper, seat with Lee seater to mag length. Shoots 75gr Hornady Match over RL-15 very well out of a Lilja custom barrel.
Clean, uniform the pockets, deburr, run through possum hollow case trimmer, chamfer inside and outside of case mouth, drop powder with Redding powder dropper, seat with Lee seater to mag length. Shoots 75gr Hornady Match over RL-15 very well out of a Lilja custom barrel.
Re: Brass prep for precision AR15
Full length resize, trim to length, uniform primer pockets, deburr flash holes. If using stick powder I weigh every charge.
Years ago Bill Wilde told me uniforming the primer pocket and deburring the flash hole did improve accuracy. Bill has a fair amount of knowledge about 223's in AR's so that was good enough reason for me to do it.
Full length resize, trim to length, uniform primer pockets, deburr flash holes. If using stick powder I weigh every charge.
Years ago Bill Wilde told me uniforming the primer pocket and deburring the flash hole did improve accuracy. Bill has a fair amount of knowledge about 223's in AR's so that was good enough reason for me to do it.
Re: Brass prep for precision AR15
So how many of you sort your brass for your AR by weight? And if so, by what increments? Also, what about off center flash holes? Do you cull these cases or does it matter?
So how many of you sort your brass for your AR by weight? And if so, by what increments? Also, what about off center flash holes? Do you cull these cases or does it matter?
Re: Brass prep for precision AR15
Tumble, FL resize with a Redding Bushing die, trim to length with a Giraud (which also chamgfers and deburrs), uniform primer pocket, remove primer crimp if LC brass, deburr flash hole inside and out, nylon or brass brush the inside of the neck (brush chucked in a drill press for speed), Headstamp sort. Once brass prep is done - then the usual prime, weight each charge (RCBS Chargemaster), seat bullets and go shoot.
I tried sorting not only by headstamp but also by weight within 1 grain and I honestly didn't see much of a difference than if I just sorted by headstamp and they were all within about 3 grs. I get .4 to .75" 5-shot groups with a Larue Stealth using the above. I typically use LC08, LC09 or Win brass with 24.0 TAC/77 SMKs.
To speed up brass prep.... I use a Giraud for trimming/deburr/chamfer and then an RCBS case mate powered tool for the rest like removing military primer crimp, primer pocket uniforming, flashhole deburing, etc.
Tumble, FL resize with a Redding Bushing die, trim to length with a Giraud (which also chamgfers and deburrs), uniform primer pocket, remove primer crimp if LC brass, deburr flash hole inside and out, nylon or brass brush the inside of the neck (brush chucked in a drill press for speed), Headstamp sort. Once brass prep is done - then the usual prime, weight each charge (RCBS Chargemaster), seat bullets and go shoot.
I tried sorting not only by headstamp but also by weight within 1 grain and I honestly didn't see much of a difference than if I just sorted by headstamp and they were all within about 3 grs. I get .4 to .75" 5-shot groups with a Larue Stealth using the above. I typically use LC08, LC09 or Win brass with 24.0 TAC/77 SMKs.
To speed up brass prep.... I use a Giraud for trimming/deburr/chamfer and then an RCBS case mate powered tool for the rest like removing military primer crimp, primer pocket uniforming, flashhole deburing, etc.
Re: Brass prep for precision AR15
I always do the above-referenced steps and group my sorted cases by .2gr increments.
I'll also check/correct neck runout with the Hornady Comparator to within .001.
I always do the above-referenced steps and group my sorted cases by .2gr increments.
I'll also check/correct neck runout with the Hornady Comparator to within .001.
Re: Brass prep for precision AR15
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killshot44</div><div class="ubbcode-body">I always do the above-referenced steps and group my sorted cases by .2gr increments.
I'll also check/correct neck runout with the Hornady Comparator to within .001.
</div></div>
Wow, and I thought I was anal. Serious question..... does sorting brass within .2 gr and neck runout within .001" really make THAT much of a difference? I could see <span style="font-style: italic">MAYBE </span>if you were a world class BR shooter at 1000yds with a custom bolt gun, but is it going to make a quantifiable difference in an AR, even a "precision" AR? I'm ecstatic if my Larue can shoot .4 and .5" 5-shot groups at 100yds on a good day and hold 3/4 MOA out to 500-600m. I personally have not seen any measurable difference sorting brass down to that level (and I've tried) in an AR or even a precision/tactical bolt gun. Are you guys able to actually see a difference on paper, or is it more a psychological thing?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killshot44</div><div class="ubbcode-body">I always do the above-referenced steps and group my sorted cases by .2gr increments.
I'll also check/correct neck runout with the Hornady Comparator to within .001.
</div></div>
Wow, and I thought I was anal. Serious question..... does sorting brass within .2 gr and neck runout within .001" really make THAT much of a difference? I could see <span style="font-style: italic">MAYBE </span>if you were a world class BR shooter at 1000yds with a custom bolt gun, but is it going to make a quantifiable difference in an AR, even a "precision" AR? I'm ecstatic if my Larue can shoot .4 and .5" 5-shot groups at 100yds on a good day and hold 3/4 MOA out to 500-600m. I personally have not seen any measurable difference sorting brass down to that level (and I've tried) in an AR or even a precision/tactical bolt gun. Are you guys able to actually see a difference on paper, or is it more a psychological thing?
Re: Brass prep for precision AR15
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ReaperDriver</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killshot44</div><div class="ubbcode-body">I always do the above-referenced steps and group my sorted cases by .2gr increments.
I'll also check/correct neck runout with the Hornady Comparator to within .001.
</div></div>
Wow, and I thought I was anal. Serious question..... does sorting brass within .2 gr and neck runout within .001" really make THAT much of a difference? </div></div>
Short answer, no it doesn't.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ReaperDriver</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killshot44</div><div class="ubbcode-body">I always do the above-referenced steps and group my sorted cases by .2gr increments.
I'll also check/correct neck runout with the Hornady Comparator to within .001.
</div></div>
Wow, and I thought I was anal. Serious question..... does sorting brass within .2 gr and neck runout within .001" really make THAT much of a difference? </div></div>
Short answer, no it doesn't.
