10mm vs 45 ACP Cartridge: Which is the better option?

by Travis Pike

December 9, 2021



While the 9mm has become the dominant handgun cartridge, some of us still love our ‘big’ bore handgun cartridges. There are only a few different cartridges we’d consider big bore when it comes to automatic handguns, and the two most dominant are the 10mm and 45 ACP. These two American cartridges represent the United States well. They are both all about power!

Now, that leads us to ask, what’s the better option? Is 45 ACP still the man stopping fighting cartridge it’s been since 1905? Or has the 80s baby known as the 10mm unseated the old man? Well, it’s tough to say without examining the two in-depth.

So let’s do just that!

10mm vs 45 ACP Spec Comparison

Spec10mm45 ACP
Bullet Diameter.4".451"
Case Length0.992"0.898"
Overall Length1.26"1.275"
Max Pressure33,000 PSI19,000 PSI

Why 10mm vs. 45 ACP

The main reason is that these are the two big-bore American automatic cartridges. They contend with each other and are even the same length. Jeff Cooper was famously a massive fan of the 45 ACP but also helped develop the 10mm. Colonel Cooper intrinsically linked the two rounds together.

Both rounds are popular with cult-like followings. The 10mm especially has tons of dedicated fans who love the ‘Centimeter.’ The 45 ACP is clearly a favored cartridge, especially when stuck in weapons like the 1911, which itself has a cult-like following.

Speaking of 1911s, the 45 ACP is without a doubt the dutiful son of the platform. However, the 10mm is the prodigal son. The 10mm finds itself in more 1911s than any other platform these days.

Heck, when you fast forward 70 years and some change, we get the famed Glock series, and the 45 ACP Glock and 10mm Glock are the same size weapon and are identical until you read the model numbers. The Glock 20 is the 10mm, and the 21 is the 45 ACP.

These two rounds seem to follow each other from one platform to another, intertwined and beloved by their respective cults. Now you may be on the precipice of joining one cult or the other, and if you need help making the decision, you’ve come to the right place.

45 ACP Review

Let us start off with the 45 ACP review. Below we are going to look into the history and purpose of this cartridge and the best ammunition for every situation.

History and Purpose 

The 45 ACP was born by the patron saint of American firearms design, John Moses Browning. He designed the cartridge in 1904, and it began production in 1905. The round was intended to replace the 38 Long Colt the Army had found to be lacking. The Army, specifically the cavalry, wanted a 45 caliber weapon.

Their desire came from the Thomspon-Legarde tests of 1904. These tests involved two officers from the Medical Corps shooting various animal cadavers with a multitude of different handgun calibers. Their testing found the 45 to be the most effective option. Although, even they noted proper training and shot placement was critical.

This led to John Browning and Colt developing the 45 ACP and the Colt 1905. The Colt 1905 was then modified, upgraded, and eventually evolved into the 1911. As we all know the 1911 was the winner of the Army’s handgun test and became the standard sidearm of the United States military.

The little round that could proved itself time and time again to be an effective fighting cartridge. The 45 ACP found its way into revolvers and submachine guns with the United Military and saw combat in both World Wars, Korea, Vietnam, dozens of Cold War skirmishes, and even after being replaced by a 9mm handgun, the cartridge continued to be used by elite units in the Global War on Terror.

The 45 ACP also served with numerous police forces, including the FBI Hostage Rescue team and LAPD SWAT. The 45 ACP continues to serve police and military units, albeit in smaller numbers these days. Even as 9mm reigns supreme, the 45 ACP hasn’t faltered or been regulated to the back of the safe, so to say.

If a significant gun company makes a 9mm, they likely make a 45 ACP version too. The 45 ACP has seen life in numerous PCCs and subguns from companies like LWRC and CMMG. Americans love the 45 ACP cartridge, and it’s doubtful the round will just fade away anytime soon.

45 ACP Cartridges

45 ACP Ammo for Self Defence

Speer Gold Dot 45 ACP
Cost Per Round
Palmetto State Armory $1.46

45 ACP Ammo for the Range

Federal American Eagle 45 ACP 230gr
Cost Per Round
Primary Arms $0.79

10mm Review

Continuing on, now let us dive into the 10mm cartridge review. We are going to look into the history and purpose of this cartridge and the best 10mm ammunition.

10mm History and Purpose

The 10mm came to be at a perfect time in 1983. Any later or any earlier, and we may have never seen it take off at any rate. The 10mm was developed by Jeff Cooper and cartridge manufacturer Norma based on what Cooper thought would be the perfect fighting cartridge. The idea was simple, let’s create a round that has better external ballistics than the 45 ACP, with more power than the 9mm.

The 10mm was released with the Bren Ten automatic pistol. However, the fellas behind the Bren Ten weren’t very good at their job. The guns took forever to produce, had issues, and some even shipped without magazines. However, ole Sonny Crockett had one on Miami Vice, and that helped the 10mm gain significant popularity. Alongside Miami Vice was the famous 1986 Miami Shootout in which FBI agents armed with 38 Specials and 9mms were outgunned by a smaller two-man team.

The FBI wanted a better cartridge, and the 10mm was fortuitous enough to exist right around the same time. The FBI adopted the 10mm along with the Smith and Wesson 1076 pistol. The original 10mm load was a 170-grain cartridge moving at 1,300 feet per second, and it hit with a whopping 600-foot pounds of energy. It’s not a big surprise the FBI found the cartridge to be effective.

However, such an effective and powerful cartridge tended to be recoil inducing. FBI agents complained and failed quals, and instead of training their Agents better, the FBI downloaded the cartridge. The FBI load was a 180 grain round traveling at 980 feet per second.

The genius at S&W figured out you need such a lengthy case for such a weak load, so the 40 S&W was created and soon conquered the Law Enforcement industry. The 10mm clung to life for years and recently has experienced a rather remarkable resurgence among handgunners with new guns and loads being developed yearly.

Great 10mm Cartridges

Sellier & Bellot 10mm Ammo
Cost Per Round
Sportsman’s Guide $0.52
Federal American Eagle 10mm 180gr
Cost Per Round
Sportsman’s Guide $0.71

10mm vs 45 ACP Ballistic Comparison

The 10mm got almost 80 more years of development than the 45 ACP, and it shows. The 10mm’s initial load is still impressive to this day, and the 45 ACP can’t touch it without some wildcat loads. The closest you can get is a factory 180-grain JHP +P load that generates about 550 foot-pounds of energy.

A 200 grain 10mm at 1,200 feet per second can strike with over 700 foot-pounds of energy. That kind of load comes with some punishing recoil, but it’s still an option. The 45 ACP simply can’t touch that kind of power. That being said, there is a line of diminishing returns, and at average self-defense distances, the 45 ACP is more than capable of being a man stopper. At these average distances, shot placement is much more important with either round than the numbers attached to it.

The one advantage of using a larger projectile is a larger hole, especially with modern defensive loads. Lucky Gunner has done some outstanding work categorizing and testing the expansion of defensive ammunition. 45 ACP JHP loads can expand up to an inch in diameter. This type of expansion is guaranteed to do more damage to a threat as it passes through the body.

There doesn’t seem to be a 10mm load capable of expanding up to an inch, with most coming in around .68 inches in expansion with a high of .81 inches in diameter.

When we move beyond standard defensive ranges, we see the 10mm offer superior performance. The 10mm has more energy at 100 yards than a 45 ACP does at the muzzle. The 10mm is a relatively flat shooting cartridge, and 100 yards bullet drop is very low. A good 180-grain load at 1,275 FPS has minimal drop.

With a Springfield TRP Operator long slide 10mm, one of my favorite things to do is make a steel target ring at 100 yards in a sitting position.

The 45 ACP does decently well at long range with hot 180-grain loads. You’ll see seven to eight inches of drop at 100 yards. With a standard 230 grain ball, you are looking at it more drop, up to a foot or so. The issue is at these ranges, the 45 ACP loses a good bit of energy and, therefore, effectiveness.

Recoil and Muzzle Rise

A true 10mm load is rather beastly. Enough so that the guys with history degrees at the FBI couldn’t handle it. I joke and tease, but objectively the 10mm has harsher recoil and muzzle rise than the 45 ACP. The 10mm’s recoil is akin to a 357 Magnum with a good deal of flash, noise, recoil, and muzzle associated with true 10mm loads.

The argument that you can download 10mm doesn’t hold water. If that’s the case, then we are arguing 40 S&W versus 45 ACP, not 10mm versus 45 ACP. 10mm is a powerful round that requires the shooter to train hard and often in how to control it. It’s a lot less friendly in compact weapons like the Glock 29. The 45 ACP Glock 30 is much more comfortable and easy to shoot.

The 45 ACP has that slow-rolling recoil, whereas the 10mm has that snap and fury. The 45 ACP allows for faster follow-up shots and at average self-defense ranges, follow up shots are important. The 45 ACP tends to be less flashy in shorter barrels as well.

Suppressed Use

If you love suppressors, then you likely already love the 45 ACP.  Stock standard 45 ACP loads are subsonic by nature and suppress very easily. When it comes to suppressing a gunshot, there are two things to worry about. The first is the normal, good ole muzzle blast. A suppressor’s task is to silence that part. The second part is the crack created by supersonic rounds.

Supersonic rounds are rather loud, and even with a suppressor, they are not necessarily hearing safe. Subsonic loads have no such crack, so they are often much quieter and easier to suppress. The 45 ACP’s stock standard 230-grain FMJ loads are subsonic and super quiet when suppressed. These loads are common, affordable, and work with any 45 ACP weapon.

The 10mm is not naturally subsonic but can be made to be. Plenty of ammo manufacturers create a 220 grain suppressed load that can be nice and quiet from a suppressed 10mm. However, it’s not common, and it’s not necessarily cheap either.

When it comes to suppressed use, the 45 ACP wins hand down.

Weapon Selection

So the 45 ACP has been around for over a century at this point. The 10mm is still a spring chicken by comparison. The Gen-X 10mm has nowhere near as many firearms available for it as the 45 ACP. Heck, there are more 1911 variants in 45 ACP then there are 10mm guns. The 45 ACP comes in various platforms, both new and old. The 10mm has also entrenched itself in the 1911 platform, as well as modern polymer frame platforms.

Both are in oddball choices like revolvers and PCCs and have been popular in various shooting sports. However, on pistol selection alone, the 45 ACP is the dominant choice. You’ll find many more weapons in 45 ACP than 10mm, including the always awesome MK23 from HK. That being said, the 10mm is no slouch, and you’ll likely be able to choose near any type of firearm you could conceivably want, except for the Mk23.

Our Take – Which Is Best

10mm vs 45 ACP Showdown

Nothing with firearms and cartridges exists in a vacuum, and there is no X is just plain better than Y. It’s all situational. If I tried, I could find reasons why 22 LR is better than 9mm, and I would do it by placing the rounds in a situational context.

The simple fact is there is no best round, but there can be the best round for a particular situation.

When To Choose 45 ACP

Price and Availability Matters

If you never want to search high and low for ammunition, go with 45 ACP. The big three in pistol rounds are 9mm, 40 S&W, and 45 ACP. 45 ACP is sold anywhere handguns are sold and often in various qualities, quantities, and different loads. 45 ACP is extremely common in both standard target loads and specialized defense loads.

45 ACP ammo also tends to be cheaper when you compare like with like in regards to projectile type and ammunition quality. 45 ACP tends to be prioritized for production during ammunition droughts as well.

Suppressor Use

As mentioned previously, 45 ACP is the better round for suppression. In fact, 45 ACP is easily the best common handgun round for suppressed use. It’s not just better than the 10mm, but better than most handgun cartridges through a suppressor. 

You Hate Recoil

The 45 ACP is a softer shooting caliber with less snap and pop to it. Admittedly, if recoil is an issue, 9mm might be the better option than either. However, between 45 ACP and 10mm, the 45 ACP is the easier to handle round.

When To Choose 10mm

Power and Range

Want to reach out and touch your target with superior power and a flat shooting cartridge? Then 10mm is the round for you, from either a handgun, a subgun, or a PCC the 10mm rocks. The power and range it offers are unbeatable for a handgun cartridge.

Hunting and Field Work

Hunting with a handgun can be a challenging and rather thrilling affair. This is commonly the realm of revolvers, but the 10mm offer an automatic option. If you are a hiker, hunter, or camper, then a 10mm defensive pistol might be an option for you as well. It’s capable of dealing with predators and vermins on both two legs and four. 

Capacity Matters

If you are of the mind that more bullets are better than fewer bullets, then 10mm is for you. On average, the 10mm can squeeze in anywhere from two to three extra rounds. Also, the 10mm is more commonly available in a double stack platform.

What About Defensive Shooting

The 10mm and 45 ACP both perform well as defensive cartridges. Does one have the edge over the other? Likely so, but the real edge comes from the guy or gal behind the gun. Shot placement matters more so than the difference in the foot-pounds of energy and size of the projectile either weapon fires.

Ping, Cling, and Pow

I love being an American. I love cultural dominance, the 2nd Amendment, and I love the 10mm and 45 ACP. I keep 1911s in both calibers and in numerous configurations because they just plain rule. Both calibers are impressive, and personally, I won’t shy away from my fandom of the 10mm. However, I can admit the 45 ACP does some things better, and I like the option of owning both.

What’s your choice? Let us know below.


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About Travis Pike

Travis is a former United States Marine Corps Infantryman and currently a firearms writer, instructor, and works in Emergency Management.

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