As a proprietary bottle-necked cartridge, the .22 TCM (Tuason Craig Micromagnum) was developed by Fred Craig of Rock Island Armory. Trading bullet mass for higher velocity, the 22TCM was developed for high-capacity semi-automatic pistols and is longer than the 9mm and designed to be fired from the Rock Island Armory line of weapons with the Para-Ordinance-style double column .38 super magazines. The .22 TCM round is based on the 5.56x45 NATO case and shortened to be the same length as the .38 Super.