I'm still a believer in knockdown power. Boxers have it and bullets have it. I don't mean it the way you necessarily believe it but if it didn't exist, people would never hit the ground unless they tripped over something. It definately doesn't exist like you see it in the movies, but to say it doesn't exist is to say being shot will have no effect on you. On the other hand, maybe you've never been knocked down.
Curiously, one of the statements made by Sykes and Fairbairn in their book was that the only guaranteed reaction to a gun shot was to double up in pain if shot in the abdomen and here I read that it had no effect on someone. So maybe there are no guarantees at all.
My father, by the way, who was an infantry combat veteran and should have known better, said a .45 would knock you down if it hit you in your little finger. But come to think of it, I've known more than one person who was missing fingers!
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.