Your rifle will serve you better than any handgun. With that said, I lived in AK 27 years and had more bear encounters than I could count. I never felt uncomfortable with a 40 S&W in the woods and have killed several moose with a Glock 22. Most guys who carried handguns for bears carried 44 mags or 454 Casulls and I know guys who have killed brown bears with 44 mags. I've killed brown bears hunting and under Alaska's Defense of Life or Property Statutes, as an LEO. All were killed with a 375 H&H, which was the rifle I grabbed when dealing with problem bears in town. I'm not sure a bullet type, with a handgun, makes a lot of difference. Brain or spinal shots will be the only ways to immediately stop a determined bear. Neither the skull nor the spine are particularly hard to penetrate, but they can be a little difficult to hit under pressure.
