I thought this was going to be about the righ to arm bears!
On a serious note I thought you should/could not hunt bears with a handgun.
I worked with some guys from Alaska and they said you should file the front sight off so it goes in smoother when the bear gets mad and puts it where the sun dont shine!
But maybe they were talking Grizzly's and Brown Bear???
I do believe S&W had a series of revolvers for that type of situation.
Product: Model S&W 500 Revolver - 4"
As big as he can shoot accurately and quickly!
I would say the MINIMUM would be .44 mag.