Everyone here is making assumptions as stated above the OP never said where he was going.
I said a .22 had dropped a bear in one shot. That is a fact. I also said dont count on it. But it CAN happen. It's just rare. BUT it goes to show with proper shot placement even the "all mighty bear" can fall to a mere .22 caliber. So if a mere .22 can do that then surely a 45ACP that had much more power could, no?
The .45LC had been around for a long time and has been used to take out many bears. Hell I remember a quote from a movie or a game "6 shots... Enough to kill anything that moves" (referring to .45LC). Yes, just a movie/game, but I do agree, 6 shots of 45 cal is enough to kill nearly anything. Nearly. I think 6 well placed shots vs a Grizzly would take it down. But will you be able to get 6 good shots? Unlikely. Get a 12 gauge and load it up with slugs then carry the .45 as a sidearm and your set! Or if you want to be really safe: a 12 gauge for main weapon, and .44 magnum for sidearm. Or even a .500 SW as sidearm. With a 12 gauge and a .500 SW I'd feel safe even in Alaska!
I guess since the OP did say only one gun, then AZAK you are right. For a 45ACP as the only weapon vs large bears? no no no! A .45ACP isn't a good "only weapon" if he's up against big browns or Grizzly bears. It still *CAN* work but bringing it as your *ONLY* gun is a bad idea. If you had a 12 gauge, and a 45ACP pistol as a side-arm you'd be fine.
Now if a 45ACP is still all you had for whatever reason it is 100 times better then having nothing at all. Much better. Still I wouldn't feel safe with it as the only weapon in large bear county. If in small bear county I'd feel okay with just a 45ACP but not vs large bear. 12 gauge with slugs would be your best bet. If you ONLY want to carry a handgun then get a .44 magnum or .500SW. It's much better than a 45ACP. Still not good as your only gun in big bear county but they are much better choice.
Last edited by Josh17; January 11, 2013 at 04:34 AM.