This is an interesting article regarding bear defense with handguns.
https://www.ammoland.com/2018/02/def...#axzz5ENWSnz2i
Note this quote towards the end:
"In this compilation of incidents, one was a failure. The .357 magnum was fired three times. The shooter was mauled after the first shot and after the second and third shots. It seems likely the shooter missed all three shots. It is the only bear defense with a pistol, that failed, that we have found.
One failure out of 35 incidents is better than a 97% success rate for pistol defenses against bears. Using a pistol to defend against bear attacks seems to be a viable option."