I'm always willing to learn and try new things to increase accuracy. Picking up from some of the discussions about weighing cases, for smokeless reloads, I am wondering if it would make sense for me to weigh cases when using black powder in fixed reloads (lead alloy bullet in the case)?

I do all of the usual preps to my cases; primer pocket and flash hole reaming, case length uniforming and annealing. I don't use any neck tension as I want the bullet to align with the bore and not with the case. I would uniform the case wall thickness but I can't think of how to do this on a tapered case and not sure if it would benefit me since I don't use any neck tension.

So what else could I try with my cases to increase accuracy that I'm not already doing? Weighing cases, to determine if they might vary in interior volume, may not be important with BP because perhaps a slight change in powder compression may not be significant?

What are others opinions here and what have they found to be important with increasing accuracy - inquiring minds what to know!

oneatatime wrote on Apr 10^th, 2022 at 12:49pm:


Highwall MVA action, RKS 30" S.S. gain-twist barrel, .40-65 Ron Long-ish custom chamber with straight-ish neck, my design but specifics cherry-picked from various reamer designs, PJ 429g mould/bullet with Lyman/Snover nose with my design shank, 60 gr 1.5 Fg Swiss, Fed 215M or CCI BR2 primers. Chamber was aligned through lathe's spindle with chamber and muzzle indicated like some 1,000 yd smokeless bench-rest shooters/gunsmiths do. Chamber was first pre-drilled, tapered bored, and then reamed using a (floating?) reamer-pusher of my design that was held by hand.

I use 16/1 alloy. I had some slumping issues when using 70g 1.5 Fg Swiss. 

My chamber also has 0.200" of freebore so this will account for powder amount differences.

I would like to know what accuracies others are getting at 200 yds. off the bench. I don't know if I'm at the limit or not.

One of the experts on the panel Mike Venturino had in his Buffalo Gun Shooting book (I think it was Butch Ulssher) said he found weighing cases didn’t do anything for accuracy that he could see.

I can’t recall that any of the others even made mention of the practice.  Somebody (IIRC) talked about buying 500 cases, culling out a few very light and very heavy ones and using the rest, but I don’t recall any comparison of groups shot with the median ones vs the culls.

You might check on the Shiloh and Historic Shooting Forums.

Premod70 wrote on Apr 14^th, 2022 at 9:22pm:


What has anyone's personal experience been with measuring case-wall thickness variation and the accuracy results from these findings?

I'm sure there is a tiny difference, but when I was playing a lot with my CPA .32-40 shooting BP from a bench rest I started off using a single case and cleaning/reloading it between shots.  I later switched to pre-charging a set of cases at home and couldn't see any change in accuracy.  With that said, I'm not a talented benchrest shooter.

Chris.

gunlaker wrote on Apr 15^th, 2022 at 10:28am:


This, and the previous post, is a bit of what I am trying to get at in that I can certainly see how case wall thickness would matter when shooting smokeless and shouldered-cases where the case-necks hold a copper-jacketed bullet tightly and in precise alignment to the bore. 

In our case, using BP and lead alloy bullets, our case necks are not perfectly straight-sided, and our bullets slug-up on firing. I, for one, do not use any neck-tension and my philosophy is to try and have the bullet align with the bore, rather than have the case influence the bullet's alignment. I have a fairly tight freebore area to help with alignment and I also load the bullet out into the leade. My chamber (and cases) does have a fairly straight neck area but this is not perfect because the case wall thickness gradually increases towards the base.

Not sure I have a sufficient argument here for not mic-ing cases for case wall thickness uniformity, and sorting, but your post, Chris, helps and perhaps others can post their experiences with this and also other things that they have tried to increase accuracy.

One other question I would like answered is that with BP and alloy bullets what is the limit of accuracy that is possible; 1/2 MOA, 1/4 MOA? I can see that when at these levels of accuracy that a lot of factors come into play such as environmental conditions, type of rest (machine and rail system), come into play and therefore this would be a very subjective? answer.

hepburnman wrote on Apr 15^th, 2022 at 11:15am:


Oh, I should have mentioned that I breach seat in my CPA's so it's a different sort of problem as the bullet never touches the case.   

John shoots smokeless which is probably way more sensitive to case capacity changes.  With BP I just don't think small changes are as noticeable for two reasons.  1) BP is not efficient and thus small changes mean less.   
2) BP just isn't as accurate.  I haven't seen anyone shooting BP groups as small as the smokeless ones that John posts.

With that said, I don't think there are too many people putting real effort into extreme accuracy with BP.  There are some, but nothing like we see with smokeless.

As far as accuracy potential, I don't think there is anyone shooing sub-moa consistently with black powder, particularly with fixed ammo and ten shot groups at 200 or further.  Sub moa groups can be done at distance and I have shot a number of them, but certainly not every time.
   
Chris.