I have shot a lot of critters with .45 ACP, 9mm, .357 and .44 mags. I LIVE in bear and cougar country and see both a lot. The pucker factor you experience with a bear or cougar staring you down at less than 20 yards is something everyone needs to experience when choosing a handgun for personal defense. I am not talking about the critter in a tree with dogs barking at it. I am talking about the critter than isn't backing down. Although they will work, a 9mm, 45 ACP, .40 Smith or .38 special seems pretty darn insignificant in such a situation. I have been there many times to say the least. They will get the job done, but they aren't going to "anchor" the critter....generally.
You have a millisecond to crumple a critter that means you harm. Basically you get one shot and it may not be perfectly placed due to adrenaline. Here is where the .357 with PROPER 158-180 grain HP bullets works pretty good, not great, but pretty good. As JJ stated, forget hard cast bullets. They are simply full metal jacket bullets in terms of performance.
The .44 magnum and .45 long Colt with 240 or 250 grain HP bullets really shine. The crumple factor is awesome and there is not doubt you made a leathal hit. The big .45's, 480's and 50's are just that, they are big, heavy, cause major flinching and are not for the faint of heart or the occasional hiker/plinker. They are for seasoned handgunners that know how to use them. The biggest badest gun in the world does you no good if you are afraid of it and can't hit a barn with it. Even the .44 is too big for most guys to shoot well. This is when I recommend a GOOD .357 of no less than 4 inches. Better to hit the critter with a decent round than to miss with a big round. It boils down to what gives you the warm fuzzy, within reason. Throw your ego away and be practical. Ask yourself how much your are honestly going to practice with a big gun to get good with it in an intense situation? I am not talking slow fire at the range, but pull that pistol and get it into action and make the shot in a couple of seconds. Shoot the biggest gun you can shoot well, leaving the ego home. My favorite is still the .44 magnum. It always decides the fight for me and I have never felt undergunned. Flinch
