Seen a fair number of gsw's(retired grouchy old nurse). Except for CNS or disabling skeletal hits IMHO the will to live was the most important factor. This is a good news, bad news, situation. While single hits from a pistol are a very iffy proposition to stop a bad guy, normally that's what they are armed with as well. Even if they get off an accurate shot and hit you first, if you're determined enough, you are probably still going to be able to defend yourself or your family. In other words his pistol isn't a magic death ray either and in all likelihood he doesn't have the experience and accuracy with his weapon most of us on the firing line do. Advantage, us.
Gaily bedight, A gallant knight In sunshine and in shadow, Had journeyed long, Singing a song, In search of El Dorado