.22 TCM

The 22TCM (.22 Tuason Craig Micromagnum) is a proprietary bottle-necked cartridge developed by Fred Craig and Rock Island Armory. Before the cartridge was commercialized, it was called the 22 Micro-Mag. Standard factory loads are 40-grain jacketed soft hollow point. Armscor has announced a new round the 22TCM9R which will be the same case as the 22TCM but have an overall length of the 9×19mm round. The company plans to release this round in summer of 2015 with a Glock 22TCM9R conversion slide to allow the 22TCM to fit in a 9mm length magazine, hence the "9R" designation. The 22TCM9R will in fact still be a 39 grain bullet but will be a fully jacketed hollow point instead.

The 22TCM is based on the 5.56×45mm NATO case, shortened so that the shoulder is at approximately the same length as a .38 Super cartridge. The cartridge is designed to feed from a Para-Ordnance-style double-column .38 Super magazine. Currently only Rock Island Armory catalogs firearms chambered in 22TCM: a 1911 style semi-auto pistol (also available with optional additional 9mm barrel and recoil spring), and a bolt-action rifle (which reportedly can use the same magazines as the pistols); and only Armscor (the parent company of Rock Island Armory) manufactures ammunition.