Oh yeah, it's a brute for sure. So I load for an M2HB also and it takes around 240gr. of US869 to move a roughly 617gr. bullet around 2.9k IIRC. 12ga. recoil my ass. The first time I had the motherfucker out I forgot to put on my ear pro after I took the can off and put the brake on... I also didn't have enough eye relief and I probably didn't shoulder it tight enough either. Well, I won't be doing that again. I couldn't hear shit for a couple weeks and it gave me a black eye. I'm lucky it didn't cause permanent deafness and a broken ocular orbit.
The HTI can handle full power M2 ammo. But you won't want to. I water 'em down to around 210 or 220 for similar loads. It's still plenty.
Elite Iron cut me a custom Harris brake (he makes the brakes for Harris) and it's indexed to the barrel and requires no shims. Has wrench flats like the can, which is also indexed to the barrel so I can swap 'em in the field easy. I'd recommend that can if you can at all do it. Elite does amazing work and it's reasonable too, he's the best kept secret really.
For a barrel, I'd look at Krieger or Lilja, I think they both do BMG barrels. You'll need the barrel extension and bolt from HTI.
If I had it to do over I'd probably just get the M107. But I've got the M2HB and it's a LOT more fun so I don't really give a shit anymore. It's nice to have though and doesn't require a tripod or an AG and it doesn't go through nearly as much ammo. FWIW, a 100rd. can of belted and loaded API with pulled projos was about $500 before the current bullshit. I load, but gearing up for that cost more than the weapons did (well, I did score enough shit for 10k rounds at once so yeah).
That USO is probably a good choice for this monster, whatever you choose just make sure it has a lifetime warranty. You may need it. The Badger rings seem to be nice.
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