A shot with quality self defense ammo, or hell, even FMJ to th pelvic region is a pretty darn good fight stopper.
Some "old hands" passed that down to us in the big sandbox as a way of stopping a bad guy clean, keeping him around to interogate, and minimizing potential for over penetration. Good deal all around.
NRA Life Member
Big Sister: "You should be sponsored by Allen"
Me: "If you can't shoot good, at least look good walking to the firing line."
Big Sister: "Can you not afford a Pelican? Then buy an Allen gun bag."