The .22 Long Rifle or simply .22 LR or 22 (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. In terms of units sold it is by far the most common ammunition in the world today. Common uses include hunting and shooting sports. Ammunition produced in .22 Long Rifle is effective at short ranges, has little recoil, and is cheap to purchase, making it ideal for training. History American firearms manufacturer J. Stevens Arms & Tool Company introduced the .22 Long Rifle cartridge in 1887.<ref name="Kokalis">{{cite book|last = Kokalis |first = Peter |title = Weapons Tests and Evaluations: The Best of Soldier of Fortune |date = January 2001 |page = 331 |publisher = Paladin Press |publication-date = 2001 |isbn = 978-1-58160-122-0}}</ref> The round owes its origin to the .22 BB Cap of 1845 and the .22 Short of 1857. It combined the case of the .22 Long of 1871 with a bullet, giving it a longer overall length, a higher muzzle velocity and superior performance as a hunting and target round, rendering the .22 Extra Long cartridges obsolete. The .22 LR uses a heeled bullet, which means that the bullet is the same diameter as the case, and has a narrower "heel" portion that fits in the case. It is one of the few cartridges that are accepted by a large variety of rifles and handguns. Popularity The .22 LR cartridge is popular with both novice shooters and experts. Its minimal recoil and relatively low noise make it an ideal cartridge for recreational shooting, small-game hunting, and pest control. .22 LR cadet rifles are commonly used by military cadets and others for basic firearms and marksmanship training. It is used by the Boy Scouts of America for the rifle shooting merit badge. The low recoil of the cartridge makes it ideal for introductory firearms courses. Novice shooters can be surprised or frightened by the noise and recoil of more powerful rounds. Beginners shooting firearms beyond their comfort level frequently develop a habit of flinching in an attempt to counter anticipated recoil. The resulting habit impedes correct posture and follow-through at the most critical phase of the shot and is difficult to correct. With high recoil eliminated, other errors in marksmanship technique are easier to identify and