.22 TCM


The .22 TCM or 22TCM is a proprietary bottle-necked cartridge created from a 5.56 NATO cartridge developed by custom gunsmith Fred Craig and Rock Island Armory for semi-automatic pistols and the Rock Island M22 TCM bolt action rifle. Before the cartridge was commercialized, it was called the 22 Micro-Mag. Similar conceptually to other bottle-necked pistol cartridges such as the larger-caliber.357 SIG, the.22 TCM trades bullet mass for increased velocity and lowered recoil.
Based on the 5.56×45mm NATO case and shortened so that the shoulder is at approximately the same length as a.38 Super cartridge, the.22 TCM is somewhat longer than the ubiquitous 9×19mm Parabellum and designed to be fired from a RIA line of firearms fed by Para-Ordnance-style double-column.38 Super magazines. A sub-variant, the 22 TCM 9R, with a shorter, more deeply-seated bullet, is designed for use in Glock magazines limited to standard-length 9mm cartridges. Standard factory loads are 40-grain jacketed soft hollow point, 39-grain for "9R".