Like you I have several pre-deal Smith and wessons. One of them saved my like in RVN. While I have never had an instance where I had to put a finger on the trigger in the USA I have used a handgun in combat and hit my targets. My big thing is practice. To keep up I go to the range at minimum 1hr every week. I do not recommend any specific gun to anyone. I know a quadraplegic who is a good shot with a .22cal revolver and that is what he carries. He can not handle anything larger in caliber and he is comfortable with it. A .22 cal slug through the brain is a better stopper than a .44 cal slug in the wall.
Stay well - Stay safe - Stay armed - Yorktown
Exactly, use the weapon that has the most firepower that you can handle. As for your friend, a gut shot with a .22 is still better than a head shot. I don't know if .22 can be bought pre-frag but if it can, and I had to carry a .22, that is what I would use. Hit under the protection of the ribs and the frags will tear into vital organs. The potential saving grace of a .22 is that you can find a revolver with high capacity that is still light-weight.
Thanks for your RVN duty.