The .22 TCM is essentially a shortened version of the 5.56 NATO, at least as far as the casing is concerned. Considered by many to be a “Wildcat” caliber, the .22 TCM was created by Rock Island Armory gunsmith Fred Craig. Originally dubbed the 22 Micro-Mag, the .22 TCM was designed to fulfil a niche that Craig had discovered: firing a .22 caliber bullet from a M1911 pistol.
Instead of using current pistol caliber casings of the time, Craig decided to use the 5.56 NATO casing. Why, you ask? In order for the caliber to be a success, it had to function perfectly through 9mm Luger magazines. And, seeing that the diameter of a 9mm and the 5.56 ( .223) are within a thousandth of an inch of each other, with the 5.56 being the smaller, this would allow for perfect functionality. Another reason for using the 5.56 as the parent case is the maximum pressure allowed, being 55,000 p.s.i. However, since the round is not a SAAMI-approved cartridge, there isn’t much load data available, or should we say professional load data. Most of the information found online regarding load metrics for this round are done by hobbyist. Therefore, is you are loading a .22 TCM, do so extremely carefully and thoughtfully. Yet, it will still continue to be a popular wildcat cartridge, given its affordability and ease of use.
Each box contains 100 once fired brass shell casings. Head stamps are mixed. This is unprocessed brass sourced from commercial shooting ranges. The casings have been washed and polished, but not resized and may still contain the spent primer.
It is recommended that all brass be inspected prior to being reloaded and fired.