Dude, You've been watching too many movies and listening to too many rambo stories. :no: I have personally seen a man take 2 Hydra-shok +p 45 ACP's in the chest and run about 20 feet before collapsing. I saw a man take two full blasts of 12 ga. 00 buckshot in the gut from a double barrel at about 12 feet. He fell foward on his hands and knees, got up and ran across a parking lot before collapsing. ( oh well. so much for the impact knocking you down) I talked with witnesses who saw a man take one 22 long rifle round dead center in the chest and collapse. 3 members of my family(including me) have shot people during armed confrontations with 45 hardball, and all three bad guys went down immediately with one shot into the chest cavity, yet a neighbor down the street shot a bad guy with a 45 in the chest, and the guy drove himself to the hospital and survived to go to jail. So, tell me, which one will it be when he has to shoot a guy with his 45 and +p rounds? There are no absolutes, nor death rays. Put it out of your mind, that what you shoot him with is the magic formula or "overkill". The formula is: Hit your target, use the heaviest/ hottest load you can reliably handle, the best gun you can afford, the best ammo, and do what you have to do.
As far as +p's in the GI 45, I have several. I really like Hornady TAP, and Cor-Bon +p ammo in my 1911's. And By the way, I would never go into the woods with "Grizzly Bears", armed with a 45 auto, unless you want Park Ranger Investigators digging your remains AND your 45 out of the bears manure on a later date. Second, NONE, I repeat, NONE of the 45 auto shootings I witnessed had an exit wound. Much less the "3 people" behind him. That ain't ballistics nor how it works.
Carry your Hornady TAP Ammo and relax. If you shoot a good bit of it in practice, change out your recoil spring every 500 rounds or so, or put in a little heavier spring and make sure it's reliable.