The problem with a leg shot is that a man will bleed to death pretty quickly if you shoot him in the leg unless you have surgical precision or completely miss an artery. Even a 9mm will open up a leg pretty significantly unless it is just flesh.
And, you don’t want to do any life saving on a dirtball. And, if you are held liable the special damages (doctor bills lost wages etc) for a DOA are about 10% of what they will be for a survivor with one leg.
Shot put his brains on the wall. End of story.
Baring firearms, a neck stomp would work just as well.
Repeat as necessary.