Suppose shot is 100 yards. Suppose bullet moves 3000 feet per second it will take 1/10 second to go 100 yards. Deer has reaction time in the range of 50 milliseconds. Deer's first startle response when it sees a flash is to jerk its head upward.
This gives some more information about what every hunter who's talked to other hunters for a few years hears about, unless they're the one telling the sad story of the deer who jerked his head, got his lower jaw shot off and ran away.
Neck shots are good. Aim for as close to the body as possible. Neck bones get a little bigger as you go back. For bucks in rut you have to aim at 1/3 of the distance from top to bottom instead of 1/2 like in does, because the neck is fatter below. If you've got to miss, miss a little low instead of a little high, but anything that hits the blood vessels or bones will generally bring down the deer.
I have some minor worry about contamination of the meat by cerebrospinal fluid, which adds to my tendancy to shoot for the arteries just below the spine instead of the spine itself. This is probably just superstition on my part.
My opinion only. Take it for what you paid for it.
