headshots with the pistol are always a one-hit kill -- dunno about the ak, since i never really used it. headshots are harder to get than in most games, since there's little to no auto-aim, and enemies flail around if you hit them anywhere besides the head. this aspect of the game is done really well, i think -- you can't just spray bullets in the general area of an enemy's head, and you need to aim squarely at the body if you want to put a few bullets in a guy who's rushing you