The .22 Long Rifle or simply .22 LR is a long-established variety of .22 caliber rimfire ammunition originating from the United States. It is used in a wide range of rifles, pistols, revolvers, smoothbore shotguns, and submachine guns. In terms of units sold it is by far the most common ammunition in the world today.
Rifling twist: 1:16″
Bullet diameter: 0.223 in (5.7 mm) – 0.2255 in (5.73 mm)
Rim diameter: .278 in (7.1 mm)
Neck diameter: .226 in (5.7 mm)
Base diameter: .226 in (5.7 mm)
Case length: .613 in (15.6 mm)
Overall length: 1.000 in (25.4 mm)