One important thing to remember, when dealing with a charging bear ( or Rottweilers or Pit bulls, for that matter), is not to bolt and run, that will just encourage them, like a dog that will chase a cat more if it runs. To stand there and not show fear takes some cool -headedness and we are helped along in that respect being too scared to move as well. I'm sure the grizz that charged me finally recognized that he was charging a hunter who was throwing down on him, but he probably didn't expect me to stand my ground either. Most animals that are "king of the forest" are used to everything else getting out of their way.
I used to take out trail rides and then pack for hunters in the Shoshone Natl. Forest between Cody and the East gate of Yellowstone. We would take 15-25 riders out on breakfast rides where several of 2 1/2 foot skillets were filled with sizzling bacon, sausage and eggs. I was always expecting a grizzly to show up to such a feast. I had a Redhawk .44, and a Marlin .45/70 with Barnes 400 gr. hand loads at the ready, just in case. None of the city dudes that were with us ever said they were uncomfortable about the firearms being around, many said the opposite. One time a wrangler at a neighboring ranch took a group on a week long ride up into Sunlight Basin in the Absarokee mountains north of us. I knew there were a lot of grizzlies up that way, so when I saw him again, I asked if He'd seen any. "Yeah, saw 33 of them", he said,"but might have been counting the same one a time or two". I'd hope it was all different ones, the ones that follow you are usually the trouble makers.