.22 TCM
The .22 TCM or 22TCM (.22 Tuason Craig Micromagnum) is a proprietary bottle-necked cartridge created from a 5.56 NATO cartridge developed by custom gunsmith Fred Craig and Rock Island Armory (RIA) for semi-automatic pistols and the Rock Island M22 TCM bolt action rifle. 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.[1]
22TCM | ||||||||||||
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From left: .22 TCM, FN 5.7×28mm, .223 Remington | ||||||||||||
Type | Pistol/Rifle | |||||||||||
Production history | ||||||||||||
Designer | Fred Craig | |||||||||||
Specifications | ||||||||||||
Parent case | 5.56×45mm NATO | |||||||||||
Case type | Rimless bottleneck | |||||||||||
Bullet diameter | .224 or 5.56mm | |||||||||||
Base diameter | 0.376 in (9.6 mm) | |||||||||||
Rim diameter | 0.378 in (9.6 mm) | |||||||||||
Rim thickness | 0.045 in (1.1 mm) | |||||||||||
Case length | 1.022 in (26.0 mm) | |||||||||||
Overall length | 1.265 in (32.1 mm) | |||||||||||
Case capacity | 15.2 gr H20 | |||||||||||
Ballistic performance | ||||||||||||
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Test barrel length: 22.75" rifle (higher velocity) and 5.0" pistol (lower velocity) |
Based on the 5.56×45mm NATO case and shortened so that the shoulder is at approximately the same length as a .38 Super cartridge, the .22 TCM is somewhat longer than the ubiquitous 9×19mm Parabellum and designed to be fired from a RIA line of firearms (which also included 9mm barrel swaps) fed by Para-Ordnance-style double-column .38 Super magazines. A sub-variant, the 22 TCM 9R, with a shorter, more deeply-seated bullet, is designed for use in Glock magazines limited to standard-length 9mm cartridges. Standard factory loads are 40-grain jacketed soft hollow point, 39-grain for "9R".