.22 TCM
The .22 TCM (5.56x26mm, Tuason, Craig, Micromagnum) is a proprietary bottlenecked rimless cartridge derived from a 5.56×45mm NATO (.223 Remington) parent case. It was developed by custom gunsmith Fred Craig in collaboration with Martin Tuason, the President of Rock Island Armory (RIA) and Armscor.