7.62x39 and 30-30 both have terrible ballistics...
That lots of deer have been shot by 30-30 is not a testiment to the round, but rather to the power of tradition in the selection of deer-rifle designs by hunters-who-are-not-shooters...
*PROPER* 5.56 (not that old, lightweight 55gr stuff) will allways outshoot 7.62x39...
Thousands of hi-power shooters can't be wrong on this one, if 7.62x39 could give them better scores they'd use it...
Further, comparing the (yes, rather innacurate) AK action in 5.56, 5.45, and 7.62 indicates that 7.62 is by far the worst of the 3 for accuracy...
YES, it is accurate enough for deer at 125 yards...
So is a rifled 12GA with slugs...
In the end, you basically have a 200-300yd (for an area target) cartridge out of a 16" barrel...
Either .223 or .308 are better choices, depending how much gun you think you do (or don't) need...
And yes, .223 IS legal for deer in many states, including WI (the rules up here are 'No MGs, no .22 rimfire or smaller, no 177 centerfire or smaller. No mag limit, .223 & 5.45 are both legit for deer)...
Remember that some states ban ALL rifles, or semi-autos... That doesn't mean they are a bad choice, and the '.223 ban' (generally based on flawed science about 'kenetic energy' or 'stopping power') is just as much