why don't you just run up and twist off his head, hmm? Since the crap starts at 10 ft and less, and you (or he) can close that distance in one second FLAT, and since chest hits (other than a luck hit to the spine) take at LEAST 5 seconds to physically incapacitate him thru blood loss, or loss of organ function, shooting him is a waste of time.
the REASON guys stop when shot (IF they do) in the body is PSYCHLOGICAL, he WANTS to quit his attack, cause you've hurt/shocked him enough. So work on having loads that do that very well, and work on YOUR being able to get LOTS of hits with that sort of ammo, in the ONE second that is all you will have before LUCK becomes the main determinant of the outcome, not your gear or your "skill" (of which you doubtless have very little).
the REASON guys stop when shot (IF they do) in the body is PSYCHLOGICAL, he WANTS to quit his attack, cause you've hurt/shocked him enough. So work on having loads that do that very well, and work on YOUR being able to get LOTS of hits with that sort of ammo, in the ONE second that is all you will have before LUCK becomes the main determinant of the outcome, not your gear or your "skill" (of which you doubtless have very little).