Home Forums Hunting & Shooting Ask The Gunwriters Preventing case trimming by "improving" and Nosler brass is "soft".

Who comes up with this stuff? Once again last night I have to chuckle at some of these things. I was reloading some 280 cases (Nosler) that have been fired six times (not a ton but enough). There has been ZERO appreciable stretching, and primer pockets are still as tight as day one. The rifle has a "custom" chamber and the load spits 140 gr TSX's at 3020 fps (not hot but certainly not anemic).

I've been shooting Lapua cases in the same rifle and they certainly don't last any longer and I don't have to form the Nosler brass!

Just an observation.

Nosler, or more precisely the current OEM for Nosler, has done better with their brass in recent years.

In the past I encountered soft lots of Nosler 308 and 270 Winchester cases.

Have had with no issue w/Nosler 280AI brass in a SAAMI chamber. Zero. Been using since intro.

The SAAMI part should be emphasized....

Am running 140 Noslers at book down a 24" --3200 plus change

I don't know about your particular chamber, but the issue of soft Nosler cases and improving cases to reduce stretch are two different things.

I have formed and fired a lot of improved cartridges for various Ackley and Epps designs. Improving the case - specifically, changing its shape - reduces the amount of stretch in older designs - 303 British, 30/30, Hornets, etc.

Reducing the case taper and sharpening the shoulders does slow down the flow of brass. It does not stop it however.

Experimenters don't bother much with improving cases like they once did. Among other things, cartridge designers learned that by eliminating long, gradual taper and droopy, shallow shoulder angles, they maximize the internal space and produce faster velocities. Doing so slows the brass flow and thickening case necks.

It's not rocket science. The more space available in a case, the more powder that can be put into it. All things being equal, that means you increase the bullet velocity.

Ackley's earlier designs featured a 35 degree angle, but he later changed it to 40 degrees. For some of his improved cartridges, the difference was noteworthy. For others, less so.

WRT soft brass, it's a lot to lot thing. Despite it being 2015, small variations still exist in manufacturing.

I have seen no evidence that brass "flows" from firing. My latest test was with a 30/40 Krag in a P14. The case was unsized, just de-capped, re-primed and loaded with the bullet sitting on the powder. The load was 49 grains of 4350 with a 180 grain bullet. After fifteen shots, case length was unchanged. Maybe the Krag case is too straight and the shoulder too sharp? Maybe I should cut a chamber with an even more shallow shoulder angle.
Mostly, when people speak of soft brass, they are expanding primer pockets with loads that could be expected to expand the pocket unless the brass was particularily tough. So it was that people would search for harder brass in order to use loads which were, in reality, too hot.
I was guilty of this myself. When I was loosening primer pockets in Norma brass, I switched to Winchester and could load a couple more grains. In truth, the load was too hot regardless of the brass I used. GD

The hardest, or at least the most brittle, brass that I've reloaded was the Winchester/Olin WSSM brass. Maybe it was hard/tough because Winchester/Olin loaded the WSSMs at the high end of SAAMI acceptable pressures.

Rest assured that was not the situation in what I reported earlier.

I'm talking about two different things.

Cases for all my rifles are neck sized. Cases last 20 or more reloads with no trimming. It's been many years since I trimmed a case.

SAAMI max in a Krag is 47k psi. I wouldn't expect much stretch at those pressure levels.

I’ve long suspected the major reason steep-shouldered cases don’t “stretch” much is when correctly sized they headspace more firmly, so don’t get pushed into the chamber slightly deeper by the firing pin, as can happen with slope-shouldered rounds. This is even true of the .22 K-Hornet, because the new shoulder headspaces more precisely than somewhat variable Hornet rims.

The very steep 40-degree shoulder of Ackley Improved rounds isn’t necessary, as I’ve seen this in any case with a shoulder around 30 degrees. Neck-sizing helps reduce stretching, but steep-shouldered rounds seem to resist stretching even when full-length sized—or do when FL sized correctly.

Winner winner chicken dinner.

Yes, I have found a press fit works quite well in target rifles - both rimmed and rimless. We often measured the chamber on competition rifles, so we could return the cases to a precise fit. Of course, in hunting or standard issue military rifles, you wanted a few thou of play inside.

WRT to the 303 or other rimmed cases that headspace in the rim recess, I have seen rifles with long chamber issues. Some gunsmiths and shooters mistakenly thought they had headspace problems because the cases would stretch or split. They were thinking rimless when they should have been thinking rimmed. They saw the classic stretch band, forward of the rim. In fact, the headspace was fine, but the chamber was long.

There was also a problem that happened occasionally with older rifles that were chambered for rimmed cases. This occurred when headspace was moving toward, or was excessive.

The firing pin would kick the cartridge forward several thousandths of an inch until the rim contacted the front section of the rim recess and stopped. The powder would burn and pressure would push the head backwards until it contacted the bolt face. The case would stop - jammed if you will - against the bolt head. At the same time, the longer chamber in front of the rim recess would allow the brass to stretch forward to fill the void.



Which is why I like the rimless 303 - aka as the 308 Win. It only has about 4 more degrees of shoulder, 20, compared to 16 for the 303, but combined with the thicker case walls and reduced taper, it works. It is a very efficient, no nonsense cartridge. The taper is approx. 16 thou for the 308 vs 55 thou for the 303. Stretch is reduced and you can get a better fit.

It also helps that chamber reaming is more consistent these daze too.

The last thing - especially for older firearms - is the lack of consistent chamber sizes. This can play hell on rifles firing rimmed cartridges especially. Hence the reason to find the correct fit and return the brass to this conformity - but only with target rifles.

I have been fire forming some brass for the .280 RCBS, with a false shoulder. Some of these fit a little tighter than others, I assume from brass springback. I wanted to hunt with them this fall, so I ran them all through the chamber, and after one time through, they chamber very easy. I have killed 2 deer with it, and just lack 7 having all 100 fireformed. This method eased my mind about a second shot, should I have needed one. miles

A couple years ago I had a batch of Federal .308 Match brass that expanded enough to let the primers fall out, with starting loads of Varget. And yes I double checked charge weights, powder, etc.

Then recently I was working up loads for the 7mm-08, and ran into the same issue. The primers weren't falling out but Federal cases were starting to show expansion with loads that were within book. I checked the same loads with Norma and Nosler brass, and the chrono gave reasonable results with the loads, with no case expansion.

I almost always partial full-length resize, trying to set shoulders back no more than .002", to minimize stretch and have a good fit of case to chamber.

Hey Tex,
Was that nickeled brass or no? I had some nickeled match ammo which loosened the pockets enough, with the factory load, the the brass was not reloadable. Some non-nickel brass doesn't show the same problem.
I'll be running some more tests this winter on brass stretching, brass flow, and contributing factors. Eventually, I'll report. GD

I've had the same issue with Federal .223 brass.

Now I just leave Federal brass where it lies, it's not worth picking up.