GM100M Primers in a .357 Mag

[OldMan]

I normally use CCI but can't find any, but I do have 1000 of these Federal match primers. I've read some horror stories about these being way to soft and piercing even in relatively mild loads, anyone have any experience? Powder is Alliant 2400 with 158 XTP.

 

[Oldtrader3]

I have used the Federal Gold Match small pistol Magnum primers in some really hot loads in my .357 Bisley, Super Blackhawk 7-1/2 inch, .44 mag frame. These loads ran close to 40,000 PSI and did not cause any problems, gas leaks or otherwise with 18 grains of LilGun and 158 Gr Hornady XTP bullets at 1500+ fps. These are pretty aggressive loads for any primer and I had no issues with the Federal SP Mag primers failing in any mode.

I would not try to use them in a Glock .40 S&W pistol though. Having the case head unsupported by the Glock barrel and using a mag primer in such a small case may be an issue? However, I do use the Federal small pistol Match primers is the .40 S&W for my revolver.

 

[OldMan]

Well I guess I did well getting those primers, I loaded 14 gr of 2400 and put the first 3 under 2 inches at 20 yards. For a 4" Ruger GP100 offhand, that's not bad for me! Went up to 14.5 grains and it still holding, no problems with these primers!