MachIVshooter
Member
Awhile back I finally scored a bucket list item, an LAR Grizzly Mk I .45 win mag in excellent condition. It came with a number of extras, one of which was a 10mm Auto conversion kit. Now, to me, it seems kind of silly to run that round in a massive pistol like this, especially when I have several other compact and full size 10mms. But I have wanted a 10mm Magnum ever since I knew of it's existence, and the AMT AUtomag IV, the only factory pistol ever to be so chambered are rare, very expensive and kind of ugly. Several years ago, I did build a 10" AR for which I made a custom barrel chambered in 10mm Magnum, but it was plagued with feeding issues trying to use modified 5.56 magazines, and truthfully just kinda became forgotten as I got busier with work and life. I'll revisit it at some point, I still want to do what I set out to with it and make 350-400 gr. bullets for suppressed subsonic use.
Anyway, I had been meaning to do ream the barrel on this critter for some time, but again, just really busy. Finally decided today to just take the hour or so to ream it and thread the barrel. On the magazines, I simply ripped the block out of the back and cut the feed lips a little for the longer cartridge. I will need to make a proper follower for it at some time, it's not 100% on feeding with the short follower and spring in that magazine, but it does run! I haven't chronoed out of the 6" pistol barrel yet, but in the 10" AR, loads a bit below max were pushing 200 gr. XTPs at 1.,630 FPS. It's a pretty potent cartridge!
And no, it's not very quiet with the can. Much less noise than unsuppressed, but not hearing safe at all. I designed TLX for service pistol cartridges burning less than half the powder charge, and .400" supersonic pistol bullets have a nasty sonic crack regardless of how effective the can is.
Anyway, I had been meaning to do ream the barrel on this critter for some time, but again, just really busy. Finally decided today to just take the hour or so to ream it and thread the barrel. On the magazines, I simply ripped the block out of the back and cut the feed lips a little for the longer cartridge. I will need to make a proper follower for it at some time, it's not 100% on feeding with the short follower and spring in that magazine, but it does run! I haven't chronoed out of the 6" pistol barrel yet, but in the 10" AR, loads a bit below max were pushing 200 gr. XTPs at 1.,630 FPS. It's a pretty potent cartridge!
And no, it's not very quiet with the can. Much less noise than unsuppressed, but not hearing safe at all. I designed TLX for service pistol cartridges burning less than half the powder charge, and .400" supersonic pistol bullets have a nasty sonic crack regardless of how effective the can is.
