Comparing apples to oranges there Supe. .308 and AK both fire a .30 caliber bullet. Difference is AK is designed to deliver reliable high rate of fire with reasonable accuracy for it's intended purpose, to wound the enemy.
You are right about the relative impossibility of the 1000 yard .308 shot, although the 300 yard AK, again .308, is not out of the question.
You are right about the holdover required for such long shots with lightweight bullets. Here's an example:
.308 180g bullet Mv = 3100fps 500yd v= 2251 fps holdover = 40" @ 500 yds
.224 70g bullet Mv=3399fps 500yd v=1360 fps holdover = >60" @ 500 yds.
I may have told a rock chuck story or two in my day also.
