The .22 Long Rifle or simply .22 LR (metric designa...
wikipedia - 25 May 2022The .22 Long Rifle or simply .22 LR (metric designation: 5.6×15mmR) 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.