The .22 TCM or 22TCM (.22 Tuason Craig Micromagnum) is a proprietary bottle-necked cartridge developed by custom gunsmith Fred Craig and Rock Island Armory (RIA) for high-capacity semi-automatic pistols. 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.