Federal GM205M primers

[Hawkeye Joe]

What's the hottest load (or FPS) you SAFELY used with the thinner cup Federal GM205M primers. With CCI BR4's being extinct, The 500 I have left are for matches only. Looks like it's time to work up some new 204 loads with Federal 205M's and Rem BR primers. I know the Rem BR very well, Just never tried the Federal GM205M's. I'd rather ask a few questions than shoot my eye out. I guess I'm wondering if anybody's pierced one at standard 204 velocities??

[Rick in Oregon]

Mike: Can't answer with experience, as all my fresh 204 loads with 205M's using your Benchmark and Berger 35gr load intended for my new Kimber have not been shot yet (soooon though).

However, note that Nosler used 205M's exclusively for all their 204 loads in their No.6 manual, as have some other bullet makers done in their testing/manuals.

I'd say it should not be an issue. I use the 205M's in my .223's and .223 Ackley at full pressure rat loads, and have never experienced a pierced or blown primer in any way.

Sidebar: Have you noted that there are about NO small rifle primers available since 'what's his name' got elected? Even many of the mail order houses are out of stock. This could get very ugly.

[Hawkeye Joe]

I have my 8 year supply. Hopefully only 4 will be needed

[jo191145]

Mike
You won't pierce a 205M with any book load data. Certainly not your favorite Benchmark.

Now if you foolishly try pushing a 40gn bullet past 4000fps you will. Don't ask