When I went to Russia my gun paperwork got all screwed up so I was given an AK47 to use with the advice that it held 11 rounds so if I saw a bear I should pull the trigger 11 times. I didn't take that as a real endorsement of the round....lol I never got to try out their advice...thankfully I think.
I believe you are confusing the 7.62x39 with the 7.62x54R, the x54R has more jam than the 308 and is very close to the 30-06.