Isn't there some problem with the 7.62X39 in that some bullets run from something like .309 , and others to .311?
ironglow,the bore size of the rooskie is 310..when Ruger put it into the mini 30 they gave it an 308 bore figuring it was going to be easier to get 308 dia. boolits than .310 in the U.S, I know this because I have an pre Clinton Ranch rifle in 30 rooskie and it has a .308 bore,thats why you hear people saying what terrible accuracy the 30 ranch rifle has, is because it does have terrible accuracy with the 310 boolit,but I have loaded up some good shootin .308 rounds for it...........correct me if I am wrong I believe Ruger was the first American manufacture to chamber the Russian round to take advantage of the flood of pre Clinton Chinese ammo............
My Remington 799 in 30 Rooskie's bore is 310 and much prefers this dia........................
And yes they will shoot either Diameter safely....