We have cougar in many parts of AZ and black bear up North, and while they don't get as big as their Eastern cousins, they're still big enough to ruin your day. I carry either a .45 ACP with 230gr CorBons or a S&W 686 .357 with 158 JSP for backup if I think I'll need it. One of the guys I usually hunt with carries bear spray when he knows I have a sidearm; it's the real potent stuff, but I don't know how well it'd work on a black bear.
One Canadian Web site did a study on the effectiveness of bear spray, mostly for the BC area over several years of encounters, and said it's more effective with grizzly than handguns. But they acknowledged it may have more to do with the fact that grizzlies often charge to "test" a threatening animal, and using spray or a pistol forces you to hold your ground for a moment. People often miss when they're panicking over a charging bear, so a poorly-placed pistol bullet will anger a bear that's bluffing, whereas the spray has a suffocating effect and confuses them. A black bear charging you, on the other hand, is rarely bluffing.
As I think about it, if you're in REAL DANGEROUS bear country, take two friends, and make sure you can outrun at least one of them. Have one carry bear spray, one with a 45-70 levergun or a 10-guage, and keep a .44 mag on your hip. :shock:
