Every year around this time people venture back into the mountains: to gather sheds, hunt for mushrooms, or just to give their lungs and legs a workout. Invariably, some cross paths with ornery bears.

It may seem silly to compare the 9mm to the 10mm. Even if your ballistics knowledge is minimal, you probably know the 10mm is more powerful. The best 9mm loads will push a 124-grain bullet to about ...