10mm vs .45 ACP

In a first for this series, we’re running these two semi-auto handgun cartridges through the Caliber Battle gauntlet. These might not be the best cartridges for handgun hunting or bear defense, but if you have to choose, which comes out on top?

Ballistics

If you took a random poll of gun owners, the majority would probably say that the 10mm is more powerful than the .45. In this case, the masses are more-or-less correct. The average 10mm cartridge will throw a 180- to 200-grain bullet faster than the average .45 Auto. (Side note: the .45 Auto and the .45 ACP are the same cartridge. “ACP” stands for “Automatic Colt Pistol.”)

But modern powder and bullets allow ammo makers to soup up old-timers like the .45, and some loads can compete with the faster 10mm. This .45 Auto from Federal, for example, launches a 205-grain bullet 970 feet-per-second (fps) for an energy output of 428 foot-pounds (ft.-lbs.) at the muzzle. This 10mm Auto is also marketed for personal defense, and it shoots a 180-grain bullet 1,030 fps for an energy output of 424 ft.-lbs.

The .45 can compete with the 10mm in certain matchups, but the 10mm has a higher ceiling. In “Cartridges of the World,” Frank C. Barnes lists the hottest 10mm as producing 680 ft.-lbs. of energy, 146 ft.-lbs. more than the hardest-hitting .45. The .45 Auto linked above appears to be Federal’s most powerful option (428 ft.-lbs.), but the company’s hottest 10mm is this 180-grain load designed for hunting, which produces 650 ft.-lbs. of energy at the muzzle.

It's also worth pointing out that “stopping power” is about more than projectile energy. A bullet must be travelling fast enough to reach an animal’s vital area, and the 10mm’s speed helps make sure that happens.

You don’t have to be a handloader or shoot +P+ loads to find a .45 that can compete with a 10mm. But at the upper end of each cartridge’s range, the 10mm Auto hits harder than the .45 Auto.

Winner: 10mm Auto

Shootability

If you’re familiar with our rifle Caliber Battles, you know that we define “shootability” as recoil impulse plus cartridge cost and availability. This metric is even more important when considering handgun cartridges.

Your shoulder won’t ache from firing either of these rounds in pistol-caliber carbine configurations, but handgun recoil is more difficult to control than rifle recoil. It’s also more subjective. Some folks claim to enjoy shooting wrist-breaking cartridges while others are incredibly sensitive to the jump and noise of a handgun’s report.

Anticipating palm pain can cause flinching when handgun hunting, but at least a whitetail won’t turn around and eat you. For bear defense, getting multiple shots on target quickly can mean the difference between life and death. That’s in part why MeatEater’s Clay Newcomb chose the 9mm over the .45 and the .44 Magnum. Controlling a handgun’s kick can be difficult, and two hits with a smaller caliber is almost always better than one hit with a larger one.

It's also worth mentioning that handguns that are painful to shoot aren’t fun to practice with. Your bear defense gun won’t do you much good if you’ve only shot a few rounds through it because it hurts your hand too much.

In this category, the .45 Auto beats the 10mm handily—at least on paper. According to Chuck Hawks’ recoil table, a 10mm Auto shooting a 180-grain bullet at 1,295 fps kicks with 11.4 ft.-lbs. of force while most .45 Auto options land in the 7 to 8 ft.-lb. range.

Of course, this comparison is highly dependent on the weight of the handgun. A heavy 10mm handgun can dampen recoil impulse and might feel similar to a .45 Auto from a lighter gun. But since every action must produce an equal and opposite reaction, a 10mm is usually going to be more difficult to control than a .45 for most people.

The .45 also beats out the 10mm from an ammo cost and availability standpoint. The .45 has been around since 1905, it’s been adopted by militaries around the world, and it’s commercially popular. Those advantages mean that .45 rounds will be easier to find and available in cheaper bulk options from almost every major manufacturer.

Federal, for example, offers 27 varieties of .45 Auto, the cheapest of which is $0.75 per round. In 10mm, they offer nine options, the cheapest of which is $1.80 per round.

Winner: .45 Auto

Versatility

The .45 Auto didn’t make our list of handgun hunting calibers, and its curved trajectory certainly limits its effective range (it drops about 5 inches at 75 yards but an entire foot at 100 yards). But that doesn’t mean it’s incapable of taking small and medium-sized game. Modern soft point and hollow point bullets increase efficacy, and MeatEater’s Ryan Callaghan once told me about an outfitter he knew who took a nice whitetail buck with the .45 handgun that “rattled around in his truck door.”

The .45 Auto can also be an effective bear defense cartridge. In a recent survey of 93 bear attacks, the .45 Auto was used eight times (tied for the second-most), and all defensive attempts were successful.

Still, it’s hard to deny that, as with ballistics, the 10mm Auto has a higher ceiling for both hunting and bear defense. Superior ballistics allow the 10mm to take larger animals than the .45 Auto or take the same sized animals more reliably.

Federal does not offer any .45 Auto loads for hunting, but three of their nine 10mm Auto options are marketed for hunting and bear defense. This 180-grain load uses a Bear Claw jacketed bullet designed to take medium-sized game like whitetail; this 200-grain option features a Swift A-Frame bullet for deer-sized animals; and this 200-grain cartridge uses a hard-cast bullet jacketed in polymer specifically designed for bear defense.

When I spoke with Todd Orr, a prolific handgun hunter from Montana, he assured me that 10mm is good for hogs, deer, antelope, and bears. He even took an elk with one, though he advised keeping shots to under 100 yards.

Winner: 10mm Auto

And the Winner Is…

Skill and comfort matter more in handgun shooting than in rifle shooting. A brand-new hunter who can hit a target with a rifle might struggle tremendously with a handgun. That’s why, unless you’re going after big game like elk, it will be better to use a .45 Auto you’re comfortable with than a 10mm you just bought at the store.

But if you’re new to both calibers, the 10mm’s superior ballistics and versatility make up for its loss in the shootability category. Most gun makers offer 10mm handguns, so you won’t have too much trouble finding a gun you can shoot comfortably. Some are also optics-ready, which will allow you to easily mount a red dot for more precise shots.

The .45 Auto may have won a World War, but for hunting and bear defense, the 10mm is the better option.

Overall Winner: 10mm Auto