Of Bears and Boars: The rebirth of the 10mm Auto

The 10mm is rising from the ashes and hunters are driving the resurgence

Statistically, your chances of being attacked by a grizzly or wild boar in the backcountry are fairly low, but it happens more than you might think. Recently, an infestation of pure-blood Russian wild boars escaped a game farm and overran my whitetail woods in Illinois, so for rambling the farm I dusted off the .44 Magnum S&W Mountain Gun that I carried in the grizzly bear country of Wyoming. Firing a few full-load magnums for practice was an exercise in masochism, my right thumb joint screamed bloody murder and so I loaded the ammo down until it was barely a .44 Special +P. It still hurt like hell. Yet, I routinely fire lightweight semi-auto pistols with .45 ACP +P ammo in total comfort.

How folks can routinely fire Scandium-framed .44 Magnums, .500 S&W or .500 Linebaugh hand cannons is beyond me. Having learned a thing or two about the terminal ballistics of handgun-velocity projectiles, I know darned well you cannot knock down a large, angry beast by foot pounds of energy alone. To stop a charging grizzly or boar you must either take away its VISA card or disrupt the Central Nervous System (CNS - brain or upper spine) with a deep-penetrating bullet. Even if the massive recoil of your hand cannon isn’t overly painful, it will surely hamper the precision you need to hit a small target like the beast’s brain. It is better to fire a more modest round which gives pin-point accuracy and deep, reliable penetration.

I swapped my old Mountain Gun for a Nighthawk Custom 10mm, my first love in handguns, the venerable 1911. The least expensive (and most popular) method of launching the auto-pistol equivalent of .41 Magnum-level whoop-ass is a Glock in either of two models, the full-size 20 or the compact 29. The big Glock Model 20, is about ¾ inch shorter than a standard 5 inch 1911, making it the size of Colt Commander. It’s about 10 ounces lighter and packs an impressive load of 15 rounds in the magazine plus another in the chamber. But, nothing fits me like a 1911 and 10 rounds of powerful 10mm ammo should do just fine.

10mm Test pistols: clockwise from the top: Gen4 Glock 20, Nighthawk Custom GRP, Gen4 Glock 29. Both Nighthawk and Glock now offer six-inch longslide models for those wanting the most velocity possible from the 10mm.
10mm Test pistols: clockwise from the top: Gen4 Glock 20, Nighthawk Custom GRP, Gen4 Glock 29. Both Nighthawk and Glock now offer six-inch longslide models for those wanting the most velocity possible from the 10mm.

Just what kind of power can we get from a 10mm Auto? Well, the closest revolver equivalent is the .41 Magnum which will start a 210 grain factory load at about 1200 feet-per-second from a 4 inch barrel. The magnum revolver rounds really don’t come into their own until the barrel is 6 inches or longer, which aren’t very handy to pack all day.

Buffalo Bore Ammunition loads either a 200 grain full-metal-jacket bullet or a 220 grain wide flat point cast bullet at 1200 feet-per-second, ballistic twins to standard .41 Magnum loads. Double-Tap Ammunition loads a 200 grain cast bullet to 1250 or a 230 grain to 1175 feet-per-second, approaching the 6 inch barrel .41 Magnum performance level. Equivalent power in a much more controllable pistol, with about double the on-board round count and a faster reload to boot. Modern “Heavy” 10mm loads are badass.

Hunting with a 10mm handgun, deliberately going for a kill, should probably be limited to animals not much bigger than a deer or wild pig at distances similar to those proper for archery; no more than 50 yards. There are videos out there of larger critters falling to a 10mm pistol, but I believe that is stretching ethics. In a defensive situation, of course, your skill with a 10mm may be all there is between you and a pine box (or at best, many stitches).

For defensive use against large animals that can bite you, stomp you, or stick you, a maximum penetration bullet design is essential. No hollow-point or expanding soft-point bullet will give maximum penetration through tough hide, muscle, and bones. Further, the nose design or “meplat” of the bullet is just as essential. Pointed bullets, even those with a blunt, round nose can veer from a straight path of penetration should they encounter something hard on one side of the nose. The flatter the bullet point, the truer it will track. The wider the meplat, the more damage it will impart in the formation of the permanent wound cavity.

For 10mm pistols, your best backwoods defense choices are wide meplat lead bullets which have been heat treated for maximum hardness. Untreated cast bullets are cast from more brittle alloys which can shatter on heavy bones. Next in line are full metal jacketed bullets with a flat meplat, perhaps the better choice for Glock factory barrels which are not recommended for a steady diet of lead slugs. Underwood Ammunition catalogs a 140gr machined solid copper slug listed as their “Xtreme P” load, using a Lehigh Defense projectile. Lehigh claims their radical bullet design creates massive permanent wound cavities while still penetrating deeper than almost any other design.

Fifty yards is a sensible maximum range for hunting use with the 10mm, but self-defense against big critters will likely occur much closer. Indeed, if they can’t reach you with their teeth, claws or antlers, they can’t hurt you. Testing by police agencies indicates a man with a knife can reach and harm you within 21 feet before your response time can catch up. Animals are much faster than a man, so I think you could logically argue at least a 50 foot safety zone for a pissed off bear or boar, any closer and they will have you before you can fire.

With this reasoning, we don’t necessarily need a pistol which will deliver a super tight group at 50 yards, rather one which will print a 1 inch group at 15 yards. Our target, especially on a charging animal, is the brain and/or cervical vertebrae; the animal’s central nervous system. No other hit is guaranteed to stop them.

The training drill for this form of self-defense is to hit a small target moving toward you very fast; not an easy task. A hit close to the CNS may stun the beast long enough for you to step aside and pound several more rounds into the brain or upper shoulder area to anchor it. We all know a moving target must be led, and a straight-in charging animal must be led low, the brain/spine target area is dropping lower as the distance closes. I was once charged by a vicious Doberman pincer which had already attacked a blind lady. The charge started from 75 yards out, running straight at me. I finally dropped it at 15 yards with my third shot from an AR15, once I figured out the first two missed “high” and I needed to lead it low. Even then, the last shot landed between its shoulder blades, well behind my aiming point on the head.

You must also visualize the animal’s anatomy from a 3D perspective to find the brain. With a big beast like a Bison or Brown Bear, you may need to aim for the end of its nose to drive the bullet in correctly to the brain.

Nobody said it would be easy.

If you’re not up to the task, either pack a heavy rifle or stay out of bear country. If you are up to the task, a 10mm pistol is the lightest, most comfortable sidearm you can choose for the job. At the 2015 SHOT show Glock introduced the Model 40, a six-inch longslide variation with an integral mounting system for optical sights and Sig announced four 10mm models on its P220 platform.

The 10mm is rising from the ashes and hunters are driving the resurgence.

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