I always go camping/hiking out west at least twice a year and though bears are what always comes to peoples minds they are not what I am worried about the most. Criminals, snakes, foxes, lighting strikes, mountain lions I believe in that order are still the number one threat for most. Also, like you talked about I always bring bear mace! It will be more effective to stop an attack quickly! It saved Jack Hannah’s life in Glacier if I remember correctly. Park rangers always told me it is more effective then pretty much any handgun when seconds count.
I remember seeing several years back one of those I Can't believe I survived episodes about a man up in the northwest, Alaska or Canada, can't remember was mauled by a big grizzly while moose hunting. Needless to say the bear tore half his face off and the bear was shot at close range with a .270 if I remember correctly. The authorities found the bear dead only a few hundred feet from where the man shot him.
So the .270 killed the bear but not before the man was half mauled to death. Just think about how long it takes a bear to bleed out! I assume it is really hard to hit a charging bear with a hot loaded .44mag more then once or twice if at all before it gets to you.
Just be prepared the best you can! Your in their backyard and boo boo might not like that.
Edit: Personally I would feel under gunned with pretty much all handguns and a charging grizzly bear. I would want a semi auto FAL or M1A ready to go. Or maybe even an old Browning M1918 BAR!
