.38 caliber

.38 caliber is a frequently used name for the caliber of firearms and firearm cartridges.

The .38 caliber is a large firearm cartridge (anything larger than .32 caliber is considered a large caliber). Before 1990, the standard sidearms of law enforcement agencies in the United States were revolvers that fired the .38 Special cartridge, seconded by revolvers firing the .357 Magnum, a lengthened version of the .38 Special.