Mag cases


Well-Known Member
May 3, 2001
Hi guys

Since the beginning of the year, I have had a 308 Baer heavy BR rifle which I have been trying to develop loads for. I have been loading for this with Norma 340 Wby cases that are necked down, fire formed then prepped and neck turned.

So far, I have been disappointed with the velocities I can achieve from this rifle before experiencing expanded primer pockets. For example, I am running a Lapua 185gn bullet and of have loaded this up to 81gn of H4831. With 81gn of powder, the primers just about fall out after the second firing.

By comparing this data to the 300 Wby, I don’t think the loads are excessive. I tend to think the Norma brass is the culprit. Does anyone have a suggestion for a source of match quality, full length - belted magnum cases that I could use in place of the Norma cases? I tend to think RWS cases might be the best option, as Lapua doesn’t offer anything suitable.

Judging by equipment lists of major 1000yd shoots, there are a LOT of cases that I would broadly classify as 300 Wby improved chamberings. I would think a lot of other shooters have been down this path before me. Any suggestions?



Steve Shelp

Well-Known Member
May 3, 2001
Haven't used much H4831 in the Baer case so I'm not that familiar with that load. But primer pockets on the second firing is probably the soft Weatherby/Norma brass for sure.

Some guys purposely "work-hardened" there Norma brass in a fire-forming barrel with a somewhat light load of cheap surplus military powder to blow the case out for 2 firings or so. They claim this makes the case heads harder but there not a full pressure load to prematurely open up the primer pockets. Then you can run your full house loads through the cases and they last a somewhat longer. But I can tell you froming running the line at NC andd VA club both for the last several years I've seen several case head seperations and primers leaking and all were 300 Ackleys using 300 Weatherby brass. This is the drawback of this case. If someone made good quality brass that would last for the 300 Weatherby you couldn't find a single complaint with that "300 Weatherby Improved" chambering. It's got everything going for it, except any type of case life.

myself for my LR hunting guns I now use Winchester 300 H&H or 375 H&H brass because of this reason. I had one lot of 300 weatherby brass that the primer litterly fell out of the case on the 3-4 firing in my 6.5-300. Take that same load and shot it in my Winchester cases and I'll be using that same brass this fall for hopefully a successful LR PA whitetail. I formed that brass in 91 or 92 and have 11-12 firings on it. Out of the original 100 pcs I've got 94 cases left and the primer pockets are still good enough.

There's is no easy solution. Plus I've talked with some "300 Improved" shooters that say there isn't a problem with Norma brass softness. Maybe they don't run a lot of pressure on there cases to begin with. I don't know. Myself you can't convince me otherwise, but opinions do vary on this subject.


[ 08-27-2001: Message edited by: Steve Shelp ]


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