I think the topic on head shots has detoured for post 9, 10 , and 11. We were commenting head shots and close ranges 30 yards or less. With a 308, proven ammo, proper zero, experienced (hunts regularly with success and lots of trigger time) and calm hunter, and a given opportunity... why not a head shot?
Because most of the bad head shot scenarios I have encountered were at 20 yards on baited bears where there is usually a relatively experienced hunter with a tested rifle (because we check them ALL before taking them out), and there is plenty of time to watch the animal and calm your nerves, and it still goes badly. Bears heads are constantly swinging around as they scent check, also the fact that their fur is dark and blends with shadows and many shots are taken during low light, making definition more difficult, and the angle of the head hard to determine. Note that in everyone of these bad cases, the hunter had been cautioned AGAINST taking a head shot, had been coached on proper body posture of the quarry and anatomy and proper shot placement, but still (usually due to over confidence in their shooting ability), chose to disregard advice an attempt the head shot. Most of these bad scenarios resulted in a wounded and lost animal, some were recovered after tracking and follow-up shots... in EVERY case the hunter was apologetic, and kicking themselves in the azz for not following the advice to take the high percentage shot. Having said that, I have also seen bears and deer and moose dropped straight down with head shots... many of those were purely accidental, but when gauging Risk/Reward... it just isn't there. No matter how confident you are in your shooting skills, do not take headshots in hunting scenarios, stuff can and does go wrong, and it goes wrong with headshots more than any other shot placement.