What is acceptable case neck runout for Benchrest?

[DngBat7]

I am kind of wanting to know what is considered as good case neck runout for benchrest reloading. I have gotten a lot of great advise privately from some great shooters on the forum, and my runout has improved quite a bit. At the end of the day, with custom bushing dies. I’m still getting from .001-.003. I have tried almost everything to keep it at .001, but seems to be a struggle. I am wiping the brass, light chamfer debur before sizing, amp annealing, using arkco top of line press, custom Whidden dies, carbide bushings, amp annealer, imperial wax, with and without expander balls, I can’t think of anything else to do. I say all that to say it not the equipment, It’s me or something I’m doing Also, all turned on 21 century turner. Am I getting the expected runout? Or am I definitely screwing up?

 

[mikeinct]

If you have them sorted by run out, shoot 3 groups from that lot. 0 to 1, 1 to 2, then 2 to 3 of runout. Do your test in a round robin Target one from Perfect group, target two from 1 to two lot & so forth. Start at target one group lot one & repeat. one shot per target from each lot till done. 15 shots not hard to do to get some real world data. Good Luck

 

[Murray Brook]

Redding body die /Lee collet die. Try it, it's not expensive and you will be surprised, along with good brass of course. On second though if you have the bushing die you may not need the Redding body die only the collet die.

 

[screaminweasil]

Redding body die /Lee collet die. Try it, it's not expensive and you will be surprised, along with good brass of course. On second though if you have the bushing die you may not need the Redding body die only the collet die.

Yep.....
Good advice. Cheap too

 

[INTJ]

I am kind of wanting to know what is considered as good case neck runout for benchrest reloading. I have gotten a lot of great advise privately from some great shooters on the forum, and my runout has improved quite a bit. At the end of the day, with custom bushing dies. I’m still getting from .001-.003. I have tried almost everything to keep it at .001, but seems to be a struggle. I am wiping the brass, light chamfer debur before sizing, amp annealing, using arkco top of line press, custom Whidden dies, carbide bushings, amp annealer, imperial wax, with and without expander balls, I can’t think of anything else to do. Also, all turned on 21 century turner. Am I getting the expected runout? Or am I definitely screwing up?

How are you measuring the runout of the case neck and at what point in your reloading process?

 

[WIB3]

Run an unsized case up in your sizing die but don’t cam over, leaving your in locked before you tighten it down. Helps square everything up.

 

[josebd]

put a rubber oring under the sizing die,and adjust as you normally would,with forster fl die,new lapua brass 6.5 creedmoor im getting less than .001 runout

 

[DngBat7]

How are you measuring the runout of the case neck and at what point in your reloading process?

Accuracy one concentricity gauge with a mitutoyo .0005 indicator

 

[JFrank]

Accuracy one concentricity gauge with a mitutoyo .0005 indicator

How much run out on a fired case ?

 

[6BRA]

agree less than .001

 

[JFrank]

Sooo your sizing steps are inducing an additional .001-.002 TIR …how are the targets ?

 

[DngBat7]

How much run out on a fired case ?

.0005

 

[CNC-Dude]

I would be skeptical myself, but Brian Litz said in an interview with the Ultimate Reloader a while back that they tested rounds that were out of round by as much as .015" and it made no difference in groups sizes...

 

[jackieschmidt]

I am one Short Range Shooter who has tested this more than once.

With my Rail Gun. Shooting 10 shot groups at 100 yards.

Anything from .000 to .003 doesn’t seem to affect accuracy.

My 6PPC and 30BR dies generally produce rounds that exhibit .001 to .0015.

 

[INTJ]

Accuracy one concentricity gauge with a mitutoyo .0005 indicator

Probably the only thing left that might reduce loaded round runout is an arbor press with an inline die if you aren't doing that already. That said, I am not sure you really have a problem, like @jackieschmidt mentioned.

The reason I don't have an definite answer is because I haven't measured runout in many years, and I shoot LR BR.

 

[DngBat7]

Thanks Everyone!