I forget where I was reading this, but in terms of Alaska, I heard that black bears are more likely to be looking at you for food, whereas grizzlies will be looking at you as a territorial threat.
If Tim Treadwell had had pepper spray, odds are he'd still be alive.
Timothy Treadwell - Wikipedia, the free encyclopedia
I've also seen a report from the Army that 5.56 is being reported as inadequate knockdown power in close quarters fighting in Iraq. The M4, from what I've read, isn't a particularly great weapon for house-to-house.
I don't know why the Army hasn't adopted a bullpup design, and I think it's probably time to get a round with more knockdown power for close quarters, but don't ask me. I worked with 120mm cannons. They can kill bear and have plenty of knockdown power.