I'm converting 358 Win brass into 375 Raptor brass. I had a hell of a time at first by following the standard setup of a full length sizer. Found that I needed to bump the shoulder down to get the AR pistol to cycle. Initially, it just wouldn't go into battery. I dailed the FL sizer down pretty much until the lock ring doesn't grab the threads. I believe the Hornady LNL overcams at this point likely since the die is hitting the shell holder. After that, I toss the brass into the AR chamber and let the bolt slam closed.
The pistol is a 12" x-caliber barrel, Aero precision Upper, BCG and CH. Mounted to CMMG Mk3 lower.
I'm not sure it'll cause any damage, but I certainly would like to know what the possible culprits are. Any advice?
I also found that I was having some feeding issues with it, but it seems to be related to the PMAGs themselves. Since the neck of the 308 bullet is expanded to accommodate a .375 bullet, the mags seem to bulge around .30-.50 depending how many rounds I load into it. I did notice 308 rounds do the same thing, but to a much lesser extent. In any case, I trimmed down the follow guide channel fins and it seems to work as expected. I have not shot it yet, but the mag seems to work normally, seats easily and AR cycles manually as expected.
The pistol is a 12" x-caliber barrel, Aero precision Upper, BCG and CH. Mounted to CMMG Mk3 lower.
I'm not sure it'll cause any damage, but I certainly would like to know what the possible culprits are. Any advice?
I also found that I was having some feeding issues with it, but it seems to be related to the PMAGs themselves. Since the neck of the 308 bullet is expanded to accommodate a .375 bullet, the mags seem to bulge around .30-.50 depending how many rounds I load into it. I did notice 308 rounds do the same thing, but to a much lesser extent. In any case, I trimmed down the follow guide channel fins and it seems to work as expected. I have not shot it yet, but the mag seems to work normally, seats easily and AR cycles manually as expected.
