.22 Short

.22 Short is a variety of .22 caliber (5.6 mm) rimfire ammunition. Developed in 1857 for the first Smith & Wesson revolver, the .22 rimfire was the first American metallic cartridge. The original loading was a 29 or 30 gr (0.066 or 0.069 oz; 1.879 or 1.944 g) bullet and 4 gr (0.0091 oz; 0.2592 g) of black powder. The original .22 rimfire cartridge was renamed .22 Short with the introduction of the .22 Long in 1871.

Developed for self defense, the modern .22 Short, though still used in a few pocket pistols and mini-revolvers, is mainly used as a quiet round for practice by the recreational shooter. The .22 Short was popularly used in shooting galleries at fairs and arcades; several rifle makers produced "gallery" models for .22 Short exclusively. Due to its low recoil and good inherent accuracy, the .22 Short was used for the Olympic 25m rapid fire pistol event until 2004, and they were allowed in the shooting part of modern pentathlon competitions before they switched to air pistols.