Regarding Rvssian mil-spec, what would be the smallest groove diameter you'd feel was safe to shoot it in? A pulled bullet measures .312". A pair of rifles measure .307" (slugged twice to be sure, yes that's tight for 7.62) and .3135" respectively. The .3135" shot mil-spec only fair, it is now on and really likes an NOE lead bullet sized .3155". The .307" is a new gun that has yet to be fired waiting for the last bits to cast and load lead bullets for it. In the mean time I'd like to shoot it some to check function using mil-spec, but with a delta of .005". . . I dunno if that'd be smart. The Russian bullets have an exposed lead core base. It looks like they are made to expand in the spirit of a minie ball, think they'd be forgiving of being squeezed down? Hate to mess up my new toy.
In looking for definitive barrel bore spec's there does not seem to be a consensus. .308", .310", .312" take your pick.