Hesitant to jump in, but I've shot 600 lb pigs and 2000 lb bulls with the 22. Ever been shot with one, me either, and I don't want to be. No not the ideal S.D. round but if the B.G. is amped enough to ignore a gun ,then enough to ignore a hit with a 22, then he is probably amped enough to ignore a hit with anything that doesn't shut him down. Are you sure the 9 or the 45 will do that,better odds, yes but are you sure you can hit that spot.If I were a B.G the weapon I would not like to meet is the one that the owner can use. a shot to the brain pan with any weapon will stop things, even without a brain shot a whack to the head will turn off a lot of things,if the bad guy is on top of you ,you already screwed up and it probably doesn't matter what you have, your in trouble.My first handgun was a 44 mag,not for B.G.s but for large harry critters. I soon realized that I couldn't practice enough to be good enough for bad situations,so I got a 22. And I shoot hundreds of rounds through it. For bear drills I shoot close, draw and shoot, at least 100 rnds before I break out the 44.Does that guarantee I'll stop a bear, no , but I'm willing to bet it ups my odds.The more you shoot the more comfortable you are.And i for one don't want to come up against any human that is truly comfortable with the gun in their hand regardless of cal. Alex