A friend of mine carries a Smith and Wesson 500, .50cal pistol when he is in the mountains. He says bears are so fast when they come at you that he will probably only get 2 rounds off before its on him.
It depends. Sometimes the attack is very fast, sometimes it is not. Two shots is often enough.
It is surprising how effective pistols are as a defense against bears.
This is true, right here.
A black bear snuck up on me in leaves. Their fluffy little feet make no noise.
And I carry a 357mag in the woods.
I carry a Magnum Research in .500 S&W Magnum. I prefer single action. I reload my 440 grain hard cast gas checked bullets to about 1700fps. I have no doubt about its stopping power. A .44 will do the job. Im in Northern Idaho a few miles from MT border.