Having never had to deal with any animal personally like a bear, I will relay a story about my wife's uncle Earl:

He lived in the hills in back country Eastern Tennessee. He was uneducated and a drunk. He also possessed unassailable comfidence, probably because his body had adapted to being in a state of near-constant inebriation.

There were several Black bears that lived in the area that ate garbage and ruined cookouts from time to time. People shot at them, usually with shotguns or whatever they could find, more as a deterrent or annoyance to drive them away. None were ever killed. These were usually 12 gauge shotguns loaded with buckshot.

In a state of drunkenness, Early had taken to playing with two bear cubs out of eyeshot of any "kinfolk." This continued for several minutes. Supposedly he was giving them bits of food and punctuating his play with swigs of whiskey from the heavy glass bottle we was drinking out of.

From the woods came a mother bear that assumed some sort of threatening position and walked up to Earl. The noise she made alerted other people who all came out with their shotguns and whatnot, but none had rifles. Nobody could take a shot because Earl could shake hands with this bear he was so close. She assumed some sort of position where she projected her muzzle forward and snarled at him. When this happened he stood up and casually guzzled the last few ounces of whiskey in the bottle. As he licked his lips he reached back and whacked the bear's muzzle as hard as he could with that (now) empty whiskey bottle. The bottle shattered and injured the she bear. Almost instantly she retreated from the scene with her cubs in hot pursuit, followed by volley of shotgun fire.

So for Blacks it would seem the best defense would be a heavy glass whiskey bottle. Since Grizzlies and Browns are a bit too tall for this approach, a nice purpose-built revolver like the Ruger Alaskan in 454 of with reasonable accuracy might be helpful for bear work. But I might keep the bottle just in case.