rationalskepticism.org

People survive being shot in the heart, too, and death from heart hits is rarely "instant" - it usually takes a measurable period up to about a half a minute on the outside. The only place one can reliably generate an "instant" death is by destroying the brain stem.

Guns are not the uber-reliable killers they are portrayed to be, - there is a LOT of variability in terminal ballistics. This is one of the things I'm very interested in, that I expect to keep learning more about as long as I live.