Popular cartridges have become so due to good performance. For more than 100 years, the standard self-defense cartridges have been .38 Special, 9mm and .45 ACP. Concealed carriers are looking for ammunition calibers that strike a balance between wound potential and concealed carry comfort.

The primary difference in those popular cartridges is size. Larger bullets produce more damage but also exhibit more recoil. They also tend to me more expensive and can add up in defensive shooting training. And that just about sums up any stopping power “theory.” Stopping power studies are often filled with suspect data and questionable methodology. They should not be your primary source of knowledge for deciding caliber size.

There are practical reasons for choosing medium-power cartridges that do enough damage to stop a threat. Beginners looking for more information on how to choose defensive ammo may find this Ammo 101 Guide helpful.

Rimfire Cartridges

The .22 Long Rifle and .22 Magnum are designed to take game you may hold in your hand up to animals of perhaps 50 pounds. The problem with rimfire, aside from being much too small for defense, is that it is an unreliable cartridge. Rimfire ignition isn’t as reliable as centerfire ammunition. The crimp allows the bullet to be damaged during the feed cycle.

.25 ACP / .32 revolvers / .32 ACP

While these cartridges will kill, they have a well-deserved reputation for poor results. Their primary value is as a threat.

.380 ACP

The .380 has become more popular more recently as markedly improved handguns were introduced during the past decade. The Ruger LCP MAX and SIG P365 are reliable, surprisingly accurate and easy to use well. However, the balance of penetration and expansion isn’t impressive. You may have either penetration or expansion but not both with hollow-point loadings. This cartridge offers modest recoil, but the tradeoff is poor wound potential.

.38 Special

The .38 Special is the least powerful cartridge many professionals feel comfortable recommending. There are two distinct classes of .38 Special loads. A medium-frame, 4-inch barrel revolver with heavy +P loads is a formidable defensive revolver with controllable recoil and excellent wound potential.

But the great majority of revolvers carried for personal defense are snub-nosed revolvers with a 2-inch barrel. The problem is in delivery, as these handguns are difficult to use well. The primary advantage of the .38 is that it is offered in a simple-to-use platform with controllable recoil. However, the wound potential is diminished in 2-inch-barrelled revolvers, which also offer increased recoil.

.357 Magnum

The Magnum offers the best wound ballistics of the cartridges covered. However, these ballistics are usually quoted from a 4-inch barrel. In a 2- to 3-inch barrel, the Magnum doesn’t burn powder as completely. A 125-grain bullet at 1,400 feet per second or more is reduced to 1,280 feet per second from a shorter revolver barrel. The result is great muzzle flash and blast, plus increased recoil from lighter guns.

While there are specific loads tuned for short barrel .357 Magnum revolvers, they are practically unobtainable. The .357 is at its best in a medium-frame revolver with a 4-inch barrel. Short barrel revolvers are difficult to use well.

9mm Luger

The 9mm is the most popular defense cartridge. It is a medium-powder cartridge with few vices. But while 9mm is better than its detractors claim, it is not as good as its strongest adherents believe. The 9mm is offered in some of the finest handguns in the world … as well as the cheapest. There are loads that offer an excellent balance of expansion and penetration. And while no ammunition is inexpensive these days, 9mm Luger remains less expensive than most centerfire pistol ammunition. Compared to big bores, the 9mm has less wound potential, but it offers modest recoil even in compact pistols.

The 9mm, .38 Special and .357 Magnum cartridges use the same bullet diameter (.355-.358), but velocity varies.

.357 SIG

The .357 SIG offers a velocity boost over the 9mm. And it isn’t a hard-recoiling load in full-sized pistols. The drawback is that some of the loads are designed for deep penetration rather than rapid expansion. While penetration is a pro, this cartridge uses a lot of powder for a modest gain in velocity over the 9mm.

.40 S&W

The .40 is the first of the ‘big bore’ cartridges. Wound ballistics are excellent, and the balance of expansion and penetration is good. The .40 was the first cartridge designed expressly to feed hollow-point bullets. But the 9mm eclipsed the .40 based on good ballistics and modest recoil. This cartridge is best reserved for full-sized handguns. It offers excellent wound ballistics and the ability to chamber a big bore in a 9mm-sized handgun. However, it does increase recoil, particularly in light handguns.


The 10mm offers wound ballistics comparable or superior to the .357 Magnum. It is a long-case cartridge, requiring a .45-size handgun. The 10mm is a great outdoors cartridge for protection against animals. It is a specialist cartridge demanding a great deal of time and expense to master. The advantages are wound ballistics, greater range than most pistol cartridges and penetration. The disadvantage is expense and greater recoil.

.45 ACP  

The .45 ACP offers big-bore wound potential coupled with low pressure, reduced muzzle signature, a full powder burn and excellent accuracy potential in good-quality handguns. However, a larger handgun is required to camber the .45. The .45 ACP offers modest recoil in full-sized handguns. Pros of the .45 include low pressure and excellent wound potential. Drawbacks are the size of weapon necessary to load the cartridge, recoil and expense.

.44 Special and .45 Colt

Left to right- .25 ACP, .32 S&W, .32 ACP, .380 ACP, 9mm Luger, .38 Special, 10mm, .45 ACP

In defense-sized revolvers with 3-inch barrels, these cartridges often generate a velocity as little as 650 feet per second. Wound ballistics are poor. Larger revolvers with 4-inch barrels are slow from leather and difficult to use well. Drawbacks are expense and recoil. And the only pro is wound ballistics … with some loads.

Which Cartridge Is Best for Concealed Carry?

For most gun owners looking to carry concealed, the middle ground is best. This means the .38 Special in revolvers and 9mm Luger in automatic pistols. Larger cartridges require considerable expense and training. Be cautious and do not let hyperbole affect your decision when choosing a caliber size. The gun store commando may not always recommend the best choice.