Common Handgun Calibers

.22 Long Rifle (.22LR) - The most common round commercially, it is one of the older varieties of ammunition still in use. Despite “rifle” in the name, this rimfire cartridge it is often used in both pistols and revolvers as well as rifles, and is popular because of it’s low cost, minimal recoil, and relative low noise. These characteristics also make it ideal for novice shooters to learn the fundamentals of shooting before stepping up to larger calibers. It is often used for recreational shooting (“plinking”), as well hunting varmints and small game. It is also a popular round for bullseye pistol competitions, particularly indoors. While considered by most an ineffective self-defense cartridge, it’s small size lends itself well to very concealable guns. There are those who use it for self-defense who follow the idea that some gun (however small) is better than no gun.

.380 ACP (.380 Automatic Colt Pistol, .380 Auto, 9mm Short, 9mm Kurz) - A common centerfire cartridge that is popular with those who want a lightweight pistol with manageable recoil. Designed for early blowback pistols, it is often found in guns with fixed barrels (which promotes accuracy). Some consider this the minimum caliber for self-defense, while others feel it is still too small.

9mm Parabellum (9mm Para, 9mm Nato, 9mm Luger, 9×19mm, 9mm) - Designed for the Luger semi-automatic pistol in Germany in 1902, it’s acceptance increased after WWI as many pistols and sub-machine guns were developed for police and militaries. During the 1980’s and 90’s, when pistols began to become more popular with police departments than revolvers, it was often chosen as a replacement to the .38 Special due to superior ballistics and the fact that semi-automatic pistols had become reliable enough to field as service weapons and generally had greater ammunition capacities. This cartridge is viewed by many as the minimum cartridge for reliable self-defense. A rimless centerfire round, it is probably the world’s most popular and widely used military handgun cartridge.

38 Special (.38 Smith & Wesson Special, 9×29mmR) - Probably the most famous revolver cartridge of all times (although there are some semi-auto pistols and carbines that use it as well, they are not common). While named “.38” from it’s related “heeled bullet” predecessors, the actual caliber is .357-.358, which allows it to be fired from most .357 Magnum revolvers (the reverse is not true due to the .357’s length). The .38 Special was the standard service cartridge of most police departments in the United States from the 1920s to the early 1990s. An accurate, relatively low recoiling, rimmed centerfire cartridge, it is still very popular. Many carry .38 revolvers as backups to their primary weapons, or in larger frames, as their primary weapon as they are considered by some to be more reliable than semi-automatic pistols.

.357 SIG - A relatively new round designed by SIG Sauer and Federal Cartridge, the .357 SIG uses a rimless centerfire case similar to that of the .40 S&W necked down to a 9mm bullet. It was designed to duplicate the performance of .357 Magnum load in a semi-automatic pistol. A high velocity round, it has a very flat trajectory and penetrates barriers well (but does not over-penetrate the body) which makes it popular with law enforcement agencies. While the bottleneck design aids in mitigating feeding issues, some feel the round’s recoil to be “snappier” than the larger, heavier .45 ACP. Like the .40 S&W, it is considered a “tweener” round, having some of the characteristics of the larger .45 ACP and 10mm, and some of the 9mm. Some consider it the best of both worlds, while others would just rather have the fast and light 9mm (without the added recoil), or slow and heavy .45 ACP.

.357 Magnum (.357 S&W Magnum, 9×33mmR) - Introduced in 1934, this is a very powerful revolver cartridge that makes an excellent self-defense cartridge and is considered by many as the gold standard for stopping power in handguns. It is a heavy hitting and accurate round. Guns chambered for the .357 can also usually accept the .38 Special round which is cheaper, and has lower recoil, noise and muzzle flash.

.40 S&W (.40, 10×22mm Smith & Wesson) - Developed jointly by Winchester and Smith & Wesson, it is a rimless pistol cartridge. The .40 S&W was developed from the ground up as a law enforcement cartridge designed to shoot hollow point bullets and to offer substantially better terminal performance than the 9×19mm NATO and the .38 Special, while keeping recoil levels lower than the more powerful 10mm Auto cartridge. After the 1986 FBI Miami shootout, the FBI decided a more robust cartridge was required than the 9mm and .38 Special in their service weapons. They concluded the ideal cartridge was the 10mm, but after fielding it, they found the recoil was difficult for many to control, and the larger 10mm handguns were too big in the hands for many of their agents. After lightening the load, and shortening the case, the end result was the .40. It is rapidly becoming popular with many other law enforcement agencies in the US, as many consider it the ideal between the 9mm and the 10mm in terms of ballistics and recoil. Some find the round “snappy” and unpleasant to shoot, and prefer the “push” recoil found in the .45 ACP.

10mm Auto (10mm, 10×25mm) - was originally developed by Jeff Cooper in 1983 for the ill-fated Bren Ten Pistol. It was adopted by the FBI in 1990 after the 1986 FBI Miami shootout, but due to it’s difficult to control recoil the FBI switched to the smaller .40 S&W. The medium velocity rimless centerfire round has better external ballistics with more stopping power than the .45 ACP, and is hailed by many as the ultimate defensive caliber, particularly those that reload and can tailor their ammunition to their needs. However, it has a reputation for battering guns chambered for it.

.45 ACP (.45 Auto, 11.43×23mm Automatic Colt Pistol) - A rimless centerfire pistol cartridge, it was developed in 1904 by John Browning for what eventually became the venerable Colt Model 1911. One of the world’s most effective combat pistol cartridges, this is an extremely popular handgun cartridge, viewed by many as the best all-around self-defense cartridge. It is a low pressure, heavy, slow round that combines very good accuracy and stopping power against human targets. It is also very popular for bullseye competitions, and other shooting sports.