There are no guarantees, but the object of shooting in self-defense is to take the fight out of someone, not kill them.
My money is on handguns in common defensive calibers are all puny and no one knows how many shots it will take to solve a specific problem. Bigger calibers (9mm and up) shift things in your favor and good shot placement shifts things in your favor, but there are no guarantees. Very few people (percentage-wise) die from handgun bullet wounds in the US.
My money's on crazy don't feel bullets like normal people do.
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