Albeit I agree with yer concept that the grabbers are idiots. The 7.62x39 & 30-30 WCF is almost identical and lots of bambis have been taken with the 30-30WCF.
I have a old mexican mauser with a shortened action and ultra light buggy whip barrel. It's in 7.62x39 and I have taken mulies, javalina and white tail with it. Very accurate 150yd tool for harvesting game. I reload for it with modern bullet designs and such so the standard warsaw pact issue ammo may be lacking but not too light for deer at all in brush country. Granted I'm not going to make a 300 yard shot with it but then I don't shoot at game beyond a hundred most of the time anyway unless it's sod poodles or coyotes with a proper caliber in a varmint rig.
Agreed it is an okay round but the northern deer tend a bit larger and the more common choice is the .308. The 7.62X39 can be loaded so as to be fine but in treed lots, where most deer hunting takes place up here, a bit peppier load than the mil std east bloc load is generally looked for.