I'm fairly proficient with handguns but in my limited time in big bear country I've gone with bear spray backed up with a 12 ga shotgun loaded with Brenneke slugs. Bears are pretty fast, not a lot of time for rapid follow up shots. I'm more confident in my ability to place shots accurately with a long gun than a sidearm. Still the bear spray would have been my first line of defense and luckily neither was necessary.
“I'd rather have questions that cannot be answered than answers that can't be questioned.” —Richard Feynman