.22 ILARCO
Gun ammunition
From Wikipedia, the free encyclopedia
The .22 ILARCO / 5.7x24mmRF, also known as the .22 Winchester American Magnum Special, .22 Winchester Short Magnum Rimfire, or .22 American,[2][3] was a rimfire cartridge designed in 1987 for the American-180 rimfire submachine gun. At the time the cartridge was created, the design of the American-180 had been taken over by the Illinois Arms Company, Inc., hence the ILARCO name.[4]
| .22 Winchester Short Magnum | ||||||||
|---|---|---|---|---|---|---|---|---|
 .22 WMR (left) compared to .22 ILARCO (right) | ||||||||
| Type | Rifle | |||||||
| Place of origin | United States | |||||||
| Production history | ||||||||
| Designed | 1987[1] | |||||||
| Manufacturer | Winchester | |||||||
| Specifications | ||||||||
| Parent case | .22 WMR | |||||||
| Case type | Rimmed, straight | |||||||
| Bullet diameter | .224 in (5.7 mm) | |||||||
| Neck diameter | .242 in (6.1 mm) | |||||||
| Base diameter | .242 in (6.1 mm) | |||||||
| Rim diameter | .294 in (7.5 mm) | |||||||
| Rim thickness | .050 in (1.3 mm) | |||||||
| Case length | .669 in (17.0 mm) | |||||||
| Overall length | .950 in (24.1 mm) | |||||||
| Primer type | Rimfire | |||||||
| Maximum pressure | 24,000 psi (170 MPa) | |||||||
| Ballistic performance | ||||||||
| ||||||||
History
Sometime after the Illinois Arms Company, Inc. (ILARCO) purchased the rights to the American-180 they determined a more powerful cartridge would be appropriate, which resulted in the creation of the .22 ILARCO. The new cartridge was designed so that a simple change of barrel was all that was required to switch between standard .22 Long Rifle, for which the gun was designed, and the new cartridge.
Dimensions and loading
The .22 ILARCO uses a shorter version of the .22 Winchester Magnum Rimfire case, which use the same 40 gr (2.6 g) projectile as the original .22 Winchester Magnum Rimfire cartridge.