Never been around bear other than a zoo. I watched a friend take out a 350 lb boar in Texas with a 1911. It wasn’t a very clean kill, don’t remember how many rounds but several were good hits at 30 feet. The following day with my Marlin 1894, he looked like he ran into a brick wall. I used what the owner of the land we were hunting at suggested. Buffalo bore 180 gr hard cast 357.
I would agree with others take a magnum and I wouldn’t take anything less than a lever action.
My guess would be taking on a charging bear with a 1911 best thing to do is give him the gun, make it quicker.
"The difference between stupidity and genius is that genius has its limits" Albert Einstine