Choosing the best caliber for self-defense can sometimes renew the debate of 9mm vs 10mm. These two calibers, despite being separated by just a millimeter in diameter, offer significantly different experiences in terms of performance, recoil and suitability for concealed carry. Understanding the differences between 9mm and 10mm can be crucial to making an informed decision.

The History of 9mm and 10mm

9mm Luger: A Time-Tested Choice

The 9mm Luger was designed by George Luger in 1901 as a load for his excellent P-08 military and police pistol. When introduced in Europe as a military and police cartridge, the 9mm Luger was considered a big-bore pistol cartridge, mainly because minor caliber pistols in .25, .32 and .380 ACP were preferred by military and police. But the 9mm was accepted fairly quickly.

It took much longer for the caliber to catch on in the U.S., which had been dominated for many years by large-bore cartridges developed for frontier self-defense. However, the Beretta 92 got the ball rolling when it replaced the 1911A1 .45 Automatic as the official duty pistol of the Armed Forces. By the mid-1980s, the 9mm Luger had gained traction with law enforcement.

With the introduction of the Glock 17 in 1982, the popularity of the 9mm grew exponentially for civilians as well. The 9mm Glock 17 had the power of the .38 Special revolver cartridge and was just as mild-mannered and accurate. Plus, its polymer frame made it the lightest pistol on the market, and at 17+1 rounds, it was also the highest magazine capacity.

Though the introduction of the more powerful .40 Smith & Wesson stole the 9mm’s thunder as the ultimate police and civilian self-defense cartridge, the 9mm came out on top due to its lower recoil.

10mm Auto: Power and Precision

Introduced 82 years later, the 10mm Automatic was based on a cartridge designed by Colonel Jeff Cooper. There were plenty of metallurgical and gunpowder improvements over the intervening years that allowed for the development of more powerful cartridges. Additionally, it could be chambered in conventionally sized but sturdily built handguns.

The 10mm Automatic has a much shorter and vastly different history than the 9mm Luger. Never intended for use by an average or novice shooter, Colonel Cooper had wanted his 10mm cartridge to do at 50 yards what the .45 ACP could do at 25. That desired destructive effect was a tall order considering the effectiveness of the .45 ACP in the legendary 1911A1 pistol. Despite its potential, the 10mm has remained somewhat niche, primarily due to its significant recoil and the skill required to handle it effectively.

9mm vs. 10mm Differences

While the 9mm Luger and the 10mm Auto have a mere millimeter of difference in projectile diameter, there is a much greater difference in the overall cartridge case length. The overall length of the 9mm is 19.15mm. However, the 10mm Auto is 25.20mm long — a 6mm difference. Thus, the powder capacity of the 10mm is much greater than the powder capacity of the 9mm Luger: 1.56 Cubic CM for the 10mm to 0.862 Cubic CM for the 9mm. Average bullet weights for the 9mm are generally 115 to 147 grains, while the 10mm launches bullets weighing generally from 155 to 220 grains. Comparing these cartridges is truly like comparing apples to oranges.

Today’s 10mm Auto is quite capable of doubling the kinetic energy of the standard 230-grain .45 ACP load. To find a 10mm load that would do what the original 200-grain Normal Load could, which is no longer available, would require a lot of searching. However, I did find a load that certainly was close to achieving Colonel Cooper’s vision of being comparable to a .45 ACP load.


Brand/Load Bullet Weight/Type Muzzle Velocity Muzzle Energy
Winchester USA Ammunition-Target and Practice


230-grain FMJ ball 835 feet per second 356 foot-pounds of energy
Buffalo Bore

10mm Outdoorsman



220-grain hard-cast lead 1,200 feet per second 703 foot-pounds of energy


As you can see, the Buffalo Bore Heavy 10mm almost exactly meets Cooper’s vision. The Buffalo Bore 10mm’s energy is similar to that of the .41 Magnum revolver cartridge; though neither round would be suitable for plinking or basic self-defense. Fortunately, the modern 10mm is also available in loads that are more manageable.

The Federal Premium HST 200-grain JHP has a more sedate muzzle velocity of 1,130 feet per second. At this velocity, a 200-grain bullet delivers a more controllable 567 foot-pounds of energy at the muzzle. In comparison, the Federal Premium HST 230-grain .45 ACP load delivers 890 feet per second at the muzzle for 404 foot-pounds of energy. That is in the ideal range for a shooter with a reasonable level of experience to use competently.

However, if that is too much, the Federal 124 grain 9mm HST load zips out of the bore at 1,150 feet per second, delivering a still effective but more manageable 364 foot-pounds of energy. Recoil is a significant factor when considering a self-defense caliber. The 9mm Luger is known for its manageable recoil, making it a favorite for both new and experienced shooters.

9mm for Concealed Carry: Pros and Cons

High-capacity 9mm pistols have a lot going for them. For one, the manageable recoil allows shooters to fire accurately and quickly, even under stress. As well, 9mm ammunition is more cost-effective per-shot. The 9mm can be chambered in much smaller and more concealable handguns while still controllable handguns for self-defense.

However, while the 9mm is effective, it lacks the stopping power of larger calibers like the 10mm. This is primarily a concern for those who prioritize maximum energy on target.

10mm for Concealed Carry: Pros and Cons

The 10mm, in contrast, boasts high stopping power, making it a formidable choice for self-defense. And the 10mm is versatile, offering a range of load options from high-velocity rounds suitable for defense against large animals to more controlled loads for self-defense. Its superior ballistics provide improved range, allowing for effective use at longer distances.

However, the 10mm’s high recoil presents a challenge, particularly for less experienced shooters. This increased recoil can affect accuracy and the speed of follow-up shots. Handguns chambered for often have lower magazine capacities due to the larger cartridge size, which can be a disadvantage in self-defense scenarios where multiple rounds may be necessary. The cost and availability of 10mm ammunition can also be limiting factors, as it tends to be more expensive and less readily available compared to 9mm rounds.

10mm vs. 9mm for Self-Defense

When deciding between these popular calibers for self-defense, consider recoil management, handgun size, intended use and ammunition cost. The 9mm cartridge is the current top choice as a self-defense round. It is easily controlled — depending, of course, on the side of the pistol it is used in. It is more affordable than other top choices and can do almost anything asked of it.

The 10mm is a great round too, but I believe it is better suited in most cases for an outdoorsman’s gun as defense against large angry creatures. However, if you choose to carry a 10mm for more conventional self-defense, practice extensively. Opt for a more manageable 10mm load, such as the Federal 10mm HST. The 10mm Auto can be very versatile and very effective, but it’s not for everyone.

The decision between 9mm vs 10mm for self-defense ultimately comes down to personal preference. The 9mm’s ease of use, affordability and sufficient stopping power make it a top choice for many. On the other hand, the 10mm’s raw power and versatility appeal to those who need or prefer a more robust round. Whichever you choose, ensure you practice regularly and stay proficient with your firearm.


Buffalo Bore: