I agree with those who advocate the lightest gun with adequate power. I just finished backpacking across the Wallowa Mountains in NE Oregon. I carried a Glock 36 .45 ACP. It weighs only 20 oz. (27 oz. w/ a full mag) and has a 3.8 inch barrel with a 6+1 capacity.
Thankfully I have never needed to use a firearm to defend against either an animal or a person but it seems to me that in the case of a problem black bear something that penetrates well would be what you want. Phil Shoemaker has written about handguns for brown bear defense and he advocated loads that penetrate well. Though a black bear is generally smaller I would think the same principles apply. Any load that might work on a bear should be plenty for cougars, wolves, humans etc.
I carried one mag of +P 230 grain truncated cone FMJ (from Buffalo Bore) and another mag of 230 grain Federal HST. Buffalo Bore says this FMJ load was designed with black bears in mind. There are many possibilities but my Glock 36 is light, compact and reliable. I shoot Glocks a lot so this was a natural choice for me.
