I think you would be served by any of the cartridges mentioned: .44MAG, .41MAG, or .357MAG.
A .44 loaded with 44 Specials would do well for general defensive duty, and with Mag loads would suit for black bear (although I agree with 700PSS Shooter - they usually run). The .41 is capable also. The .357 would be, IMHO, a little light for black bear except for the 180 grain loads. However, I wouldn't recommend the lighter S&W revolvers (ex. - Model 19 or 66) to carry that heavy of a load. I would go for a used "L" or "N" frame.
For heavy CCW carry, you could probably go with a 4" barrel although a 2 1/2" to 3" would conceal easier.
