My first hunch as well would be to say Noveske, if you can't get a Krieger.
But the first trip down the range with my Daniel Defense 300 M4V5 ran about 3/4" with the Remington 220 gr factory subsonic ammo. I've also got some handloads ready to try, with subsonic 220 SMK's, and I'm real curious as to what they'll do in the DD. In a CMMG, my handloads cut the group size in half, although it was lousy starting out.
Incidentally, I have found two different 300's to run just fine with the 220's loaded to mag length 2.24", as opposed to the recommended 2.080". Give that a whirl
