10mm vs. 45 ACP:Old Reliable, or New and Undeniable?

There’s no doubt that the 10mm Auto and 45 ACP each have their own strengths and weaknesses. But which one is right for you? This article will help you answer that question and know whether to get a Glock 21 or Colt Delta Elite.

10mm vs. .45 ACP Cartridge Comparison

Cartridge Specs

Comparing the specifications of these two handgun cartridges helps to clarify the differences between them. Although there are some similarities between the rounds, the most substantial difference is their maximum pressures. As you can see in the chart, the 10mm Auto has a much higher max pressure than the .45 Auto: 37,500 psi vs. 21,000 psi, respectively.

Recoil

On average, a 45 ACP 230 grain round generates 7.5 foot-pounds (ft-lbs) of free recoil energy, whereas the average 10mm 180 grain load generates 11.4 ft-lbs. That means the 10mm has over 50% more recoil than the 45 ACP. That difference will feel pretty substantial to many shooters.

Several variables can increase or decrease recoil. Muzzle velocity, propellant charge weight, projectile weight, and firearm weight all determine how much free recoil energy a cartridge can generate. For example, let’s assume we are firing two different 2.5 lb handguns. An average 10mm cartridge (10 grains of propellant, 180 grain bullet, 1,235 fps muzzle velocity) would generate 9.4 ft-lbs of recoil energy.

Conversely, a conventional 45 ACP cartridge (8 grains of propellant, 230 grain bullet, 900 fps muzzle velocity) would generate 7.7 ft-lbs of recoil energy.

A heavier firearm will reduce felt recoil. But generally speaking, the 10mm *always* kicks harder.

Trajectory

It’s no secret that the 10mm has a flatter trajectory than the 45 ACP. Its bullets are both narrower and faster than the .45 ACP’s – both reasons why they fly across a flatter trajectory toward their target. Suppose both pistols’ sights are 0.19″ high, and you are aiming at a 50-yard target:

• 45 ACP with a 185 grain bullet and 900 fps muzzle velocity will rise approximately 1.4″ at 25 yards and drop -12.3″ at 100 yards
• 10mm with a 180 grain bullet and 1,245 fps muzzle velocity will rise approximately 0.7″ at 25 yards and drop -6.7″ at 100 yards

Accuracy

Accuracy is a pretty big deal. Unfortunately, it’s a bit challenging to say which cartridge is more accurate, as much of that depends on the shooter and their firearm.

Go to the range and see which handgun round works better for you. Your own impression outweighs anything this article could tell you.

10mm vs .45 ACP Stopping Power

Both the 10mm and the .45 ACP can deal enough damage to instantly stop a threat. The 10mm has roughly 100 ft-lbs more muzzle energy than most .45 ACP rounds – but that’s not all that counts.

Shot placement is much more important than energy transfer. The most powerful handgun in the world will prove useless if you don’t hit your target. I’d rather land one great hit than 16 mediocre ones.

Ammo selection also plays a pivotal role. For example, despite having higher striking energy, a Federal American Eagle 10mm 180 grain FMJ bullet’s inability to undergo terminal expansion means it isn’t as well equipped for defense as a Hornady Critical Defense .45 ACP 185 grain FTX JHP load.

It is interesting to note that the 10mm Glock 20 is the most popular semi-auto handgun for bear protection sold in Alaska. If you’re heading into the woods and are concerned about crossing paths with an angry grizzly, then a 10mm is probably the better choice. However, if you’re only concerned about two-legged varmints causing you trouble, then the 45 ACP is more than enough.

Defense

Ultimately, determining which is the better round for defense is up to the shooter. Both are adequate threat stoppers. With that said, the .45 ACP’s weaker-yet-adequate striking power and softer recoil make it the better choice for most shooters.

The one significant instance is in bear country. The 10mm Auto is the more popular option for bear defense because it penetrates deeper and has more stopping power.

Ammo Cost and Availability

The .45 ACP is the clear winner of this category. As the more popular cartridge, ammo and firearms chambered for it are both easier to find.

Every big manufacturer loads .45 Auto ammunition in a variety of designs and price points. 10mm Auto ammo is more challenging to find in large quantities and at comparable price points. This is a non-issue if you’re into handloading, of course. (If you’re looking to purchase large quantities of .45 ACP, be sure to visit our bulk .45 ACP ammo page!)

Best 10mm and .45 ACP Handguns

Top 10mm Auto picks:

• Glock 20 or 29
• Springfield XD-M Elite
• Colt Delta Elite
• FN 510
• Smith & Wesson M&P 10mm M2.0

Top 45 ACP picks:

• Glock 21 Gen 5
• 1911 by any reputable brand
• HK45
• FNX-45 Tactical
• Walther PPQ

10mm vs. 45 ACP Ballistics

Take a gander at the following tables to better understand the differences in these two rounds’ ballistics. Take care that these data come from ammo manufacturers. Actual performance can differ considerably from that which is advertised (especially if your firearm has a different barrel length than whichever test barrel the manufacturer used to record their own data).

Read the full breakdown: 10mm vs. 45 ACP: Old Reliable, or New and Undeniable?

Source: https://freedombunker.com/2025/08/04/10mm-vs-45-acp/