If you are specifically buying a handgun for grizzly defense, you'd want a .50 S&W, .460 S&W, .454 Casull or a .44Mag. Basically, as much firepower as you can accurately shoot. Power means squat if you can't hit the broad side of a bear.

Otherwise, carry whatever you have. I carried my .40S&W Glock 23 last year, and will again this year. The local guy I was with had a .357Mag.

Basically, a grizz will usually not screw with you unless you surprise it. We had people seeing them all around us, we made a good amount of noise whenever walking in the dark or daylight when we didn't expect to see game and never saw them -- they move off when they hear you.

If one really wants you, no handgun will really be enough, but any handgun is better than your fingernails.