.22 caliber

A 22 caliber, or 5.6mm caliber, is a small, extremely common size of ammunition, fitted to firearms with a bore diameter of 0.22 in (5.6 mm). It is the most common bore for rimfire ammunition, and has gained popularity in the air gun discipline as a hunting/field target/HFT pellet caliber.

.22 in caliber rimfire variations include:

.22 Long Rifle (LR), the most common cartridge type of this caliber, often referred to simply as ".22 caliber"
.22 BB (Bulleted Breech Cap)
.22 CB (Conical Ball Cap)
.22 CB cap, an American rimfire cartridge
.22 Long, same length, but lighter bullet than .22 LR
.22 Extra Long, an American rimfire rifle and handgun cartridge
.22 Short, used mostly in pocket pistols and mini-revolvers
.22 Winchester Rimfire, an American rimfire rifle cartridge
.22 WMR, (.22 Winchester Magnum Rimfire) a cartridge that is longer and more powerful than a .22 LR
.22 Winchester Automatic, an American rimfire rifle cartridge

.22 inch centerfire cartridges include:

5.56×45mm NATO, an intermediate cartridge widely used in AR-15 style rifles
.22 Accelerator, a special loading of the .30-30, .308, and .30-06 cartridges that is manufactured by Remington
.22 Eargesplitten Loudenboomer, a cartridge for a rifle
.22 Hornet, a powerful variation, also known as 5.6×35R mm 5.728mm
.22 Remington Jet, an American centerfire revolver and rifle cartridge
.22 BR Remington, a wildcat cartridge commonly used in varmint hunting and benchrest shooting
.22 Savage HP, a.k.a. 5.6×52R, .22 Savage Hi-power, .22 Imp, a cartridge similar to the 22 Hornet introduced by Savage in 1912
.22 Spitfire, an American rifle cartridge
.22 PPC, a firearm cartridge used primarily in benchrest shooting
.22 TCM (a.k.a. .22 Micro-Mag), a 9mm diameter case necked to a .22 caliber bullet and designed to load into standard 9mm magazines; currently proprietary of Rock Island Armory and accommodating of that company's pistols and carbines also sold with 9mm barrel swap kits.

See also