Some commercial {Ruger} rifles have been made with .308 groove bbls and chambers with neck relief for safe firing of .310 standard 7.62x39 ammo. Tolerance being what it is, the safety feature to be most concerned with here is chamber neck relief.

The 7.62x39 is a very accurate round. We used a CZ527 for some years and shot coyotes, grounds squirrels, stray dogs and deer with it. If you've never hunted with it and decide to, you might be surprised how lethal the round is with sp ammo. Great deer round.