Caliber Battle: 10mm vs. .45 ACP

The 9mm Luger might be the queen of modern pistol cartridges, but it’s far from the most powerful. If you want to start hunting with firearms or want something with a little extra oomph for bear defense, the 10mm Auto and .45 Auto are two popular options.

For the first time in this series, we’re running both of these semi-auto pistol cartridges through the Caliber Battle gauntlet. These may not be the best cartridges for firearm hunting or bear defense, but if you have to choose, which one comes out better?


If you did a random survey of gun owners, most 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 gunpowder and bullets allow ammunition manufacturers to improve on older ones like the .45, and some loads can compete with the faster 10mm. This .45 Auto from Federal, for example, fires a 205-grain bullet at 970 feet per second (fps) for an energy output of 428 foot-pounds (ft-pounds) at the muzzle. This 10mm Auto is also marketed for personal defense and fires a 180-grain bullet at 1,030 fps for a power 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 that produce 680 foot-pounds. of power, 146 ft-lbs. more than the more powerful .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 in the mouth.

It’s also worth noting that “stopping power” is more than just projectile energy. A bullet must travel fast enough to reach an animal’s vital area, and the 10mm velocity helps ensure 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 top end of each cartridge’s range, the 10mm Auto hits harder than the .45 Auto.


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

You won’t get shoulder pain firing any of these rounds in pistol-caliber carbine configurations, but pistol recoil is harder to control than rifle recoil. It is also more subjective. Some people claim to enjoy shooting wrist-breaking cartridges, while others are incredibly sensitive to the jump and noise of a pistol shot.

Anticipating pain in the palm of your hand might make you wince when hunting with a pistol, but at least a whitetail won’t turn around and eat you. For bear defense, taking multiple shots at the target quickly can mean the difference between life and death. That’s partly why Clay Newcomb of MeatEater chose the 9mm over the .45 and .44 Magnum. Controlling the kick of a pistol can be difficult, and two shots from a smaller caliber is almost always better than one shot from a larger one.

It’s also worth mentioning that guns that are painful to shoot are not fun to practice. Your bear defense weapon won’t do you much good if you’ve only shot a few rounds at it because your hand hurts too much.

In this category, the .45 Auto easily beats the 10mm, at least on paper. According to the Chuck Hawks recoil chart, a 10mm Auto firing a 180-grain bullet at 1,295 fps kicks in at 11.4 foot-pounds. of force while most .45 Auto options land in the 7 to 8 ft-lb range. range.

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

The .45 also outperforms the 10mm from an ammunition cost and availability standpoint. The .45 has been around since 1905, has been adopted by militaries around the world, and is commercially popular. Those advantages mean that .45 rounds will be easier to find and will be 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.


The .45 Auto isn’t on our list of handgun hunting calibers, and its curved trajectory certainly limits its effective range (it drops about 5 inches at 75 yards but drops a full foot at 100 yards). But that does not mean that it is incapable of hunting small and medium animals. Modern soft-point, hollow-point bullets increase effectiveness, and MeatEater’s Ryan Callaghan once told me about a vendor he knew who took a nice whitetail deer with the .45 pistol that “rattled on 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 second place) 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 size animals more reliably.

Federal does not offer any .45 autoloaders for hunting, but three of its nine 10mm auto options are marketed for hunting and bear defense. This 180-grain load uses a Bear Claw jacketed bullet designed to hunt medium-sized game such as whitetails; this 200-grain option features a Swift A-Frame bullet for deer-sized animals; and this 200-grain cartridge uses a polymer-coated hard-cast bullet 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 bear. He even took a moose with one, though he advised keeping shots under 100 yards.

And the winner is…

Skill and comfort matter more in pistol shooting than they do in rifle shooting. A novice hunter who can hit a target with a rifle might have a very difficult time with a pistol. That’s why, unless you’re after big game like moose, you’ll be better off using a .45 Auto you’re comfortable with than a 10mm you just bought from the store.

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

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

Outright Winner: 10mm Car