.38 Special (pronounced "Thirty-eight Special", 9.1×29.3mmR) is a rimmed, centerfire cartridge designed by Smith & Wesson. It is most commonly used in revolvers, although semi-automatic pistols and some carbines also use this round. The .38 Special was the standard service cartridge of most police departments in the United States from the 1920s to the 1980s. In other parts of the world, particularly Europe, it is known by its metric designation 9x29mmR.
Despite its name, its caliber is actually .357–.358 inches (9.0678 mm), with the ".38" referring to the approximate diameter of the loaded brass case. This came about because the original .38-caliber cartridge, the .38 Short Colt, was designed for use in converted .36-caliber cap-and-ball (muzzleloading) Colt 1851 Navy Revolvers, which had cylindrical firing chambers of approximately .374 inch diameter, requiring "heel-based" bullets, the exposed portion of which was the same diameter as the cartridge case (see the section on the .38 Long Colt). Except for its length, the .38 Special case is identical to that of the .38 Long Colt, and to the .357 Magnum which was developed from the earlier cartridge in 1935. This allows the .38 Special round to be used in revolvers chambered for the .357 Magnum (but not the reverse, the longer length prevents potential accidents from the significantly higher pressure generated by the .357 Magnum cartridge).
The .38 Special was introduced in 1902 as an improvement over the .38 Long Colt cartridge which, as a military service cartridge, was found to have inadequate stopping power during the Philippine-American War. Although it was introduced sixteen years into the smokeless powder era—France adopted the first smokeless powder military rifle cartridge, the 8x50mmR Lebel, in 1886—the .38 Special was originally loaded with black powder, but was offered loaded with smokeless gunpowder within a year of its introduction. The .38 Special is very accurate in a quality revolver, produces little recoil, and remains the most popular revolver cartridge in the world more than a century after its introduction. It is used for target shooting and formal target competition, for hunting small game, and for self-defense.
In the 1930s, heavy framed revolvers oriented toward target shooting, such as the Smith & Wesson 38/44 Heavy Duty, allowed development of a higher pressure (and therefore higher power) version called the .38 Special Hi-Speed and eventually, the .357 Magnum. These .38 revolvers, built on a larger frame originally designed for the .44 Special, survived for about three decades before the .357 revolvers outdid them in sales. Today, versions of this cartridge loaded to slightly higher pressure are available, called .38 Special Overpressure ammunition (+P); these are usable in .38 revolvers rated +P and in .357 Magnum revolvers.
Because the .38 Special also works in .357 Magnum revolvers, it is popular with users of the .357 Magnum for the reduced recoil, lower noise, and lower cost. A number of lever action rifles are also chambered in .357 Magnum and .38 Special.
To this day, it is the most widely produced small-arms caliber in the world, with every nation with an arms industry, formal or otherwise, having produced it.
Due to its black powder heritage, the .38 Special is a low pressure cartridge, one of the lowest in common use today at 17,000 PSI. By modern standards, the .38 Special fires a medium sized bullet at rather low speeds. The closest comparisons are the .380 ACP, which fires slightly lighter bullets slightly faster than most .38 Special loads, and the 9mm Luger, which fires a bullet that is generally somewhat lighter but significantly faster. Both of the latter are usually found in semi-automatic pistols; the 9mm in medium-frame service pistols (and usually compact variants as well), and the .380 ACP in ultra compact semi-automatics.
The higher-pressure .38 Special +P loads at 20,000 PSI offer about 20% more muzzle energy than standard-pressure loads and places between .380 ACP and 9mm as far as terminal performance; it fares very slightly better than a standard 9mm loading.
|Cartridge||Bullet weight||Muzzle velocity||Muzzle energy||Max pressure|
|.38 Short Colt||181 ft•lbf (245 J)||7,500 CUP|
|.38 Long Colt||201 ft•lbf (273 J)||12,000 CUP|
|.38 S&W||206 ft•lbf (279 J)||14,500 PSI|
|.38 S&W Special||310 ft•lbf (420 J)||17,000 PSI|
|.38 Special +P||351 ft•lbf (476 J)||20,000 PSI|
|.380 ACP||178 ft•lbf (241 J)||21,500 PSI|
|9 mm Parabellum||349 ft•lbf (473 J)||35,000 PSI|
|.357 Magnum||639 ft•lbf (866 J)||35,000 PSI|
Experience has proven that it is reasonably effective for self-defense purposes, provided shot placement is correct and a load is used that provides adequate penetration. Only a minority of US police departments now issue or authorize use of the .38 Special revolver as a standard duty weapon, most having switched to the higher-capacity and faster-reloading semi-automatic pistols in the 9 mm, .357 SIG, .40 S&W, and .45 ACP cartridges. It is still common in security use by guards who value the perceived reliability and simplicity of a revolver, and by private citizens for concealed carry and police for secondary/backup handguns because its recoil when fired from very small and lightweight revolvers is considered much more manageable than more powerful cartridges.
- .38 Smith & Wesson Special
- .38 S&W Special