10mm loads

Guns Magazine, Dec, 2008 by Jeff John

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Q: What is the proper ammunition to use in a 10mm Glock 20 for defense against black bear, mountain lions and wild dogs? Should I choose a heavy hollowpoint, FMJ or light hollowpoint? What velocity is necessary for each type to make it effective? Can you recommend any specific brand or type of ammo?

CH

Colorado

A: A couple of things to remember are the animals you speak of are all constructed very differently, so one load won't be optimum for all. Dogs and cats are both very thin skinned and dogs are generally going to be much, much lighter, too. If you ever have to defend yourself from a mountain lion, it'll probably be at contact range if you're lucky enough to spot it first.

If it's wild domestic dogs, they're probably in a pack and it's a good thing you have a Glock. Although I have no data, I suspect every 10mm load except the Glaser Safety Slug will shoot through the biggest dog from stem to stern and probably the same for a cat. I doubt either animal will materially slow a bullet from a broadside shot. Bears are another story mostly because their bones are heavier and they can have a lot of fat later in the year. Penetration is important here.

Both CorBon and Hornady load premium 10mm ammo designed for hunting and self defense. If I were to have one load, it would probably be either the 180-grain or 200-grain Hornady XTP or the CorBon Hunter or Traditional Defense ammo in similar weights, whichever shoots the most accurately. You don't say if you have adjustable sights, but if you don't, shoot the load that shoots to the sights best. A problem with ultra light 115- and 135-grain bullets is they generally shoot very low.