Aside from the
head area the
c.o.m. is also the recommended
point of aim for
defensive shooting, called the
A zone, which is pretty much the center of a
human torso.
While instant incapacitation is still your goal in any defensive shooting aiming for the head is not very practical as the high adrenaline levels pumping in your veins combined with a small and highly mobile target does not make for high hit probability.
Because of the human body's amazing stretchability, one shot stops are not all that common as Hollyweird might have you believe. The rule of thumb is keep on firing until the threat is neutralized. As always, remember that you do not shoot to kill, you only shoot to stay alive.