.22 TCM

22TCM
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	0.224 in (5.70 mm)
Neck diameter	0.255 in (6.48 mm)
Shoulder diameter	0.362 in (9.19 mm)
Base diameter	0.376 in (9.55 mm)
Rim diameter	0.378 in (9.60 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 H2O
Ballistic performance
Bullet mass/type Velocity Energy 40 gr (3 g) Pointed flat nose 2,800 ft/s (850 m/s) 696 ft⋅lbf (944 J) 40 gr (3 g) Pointed flat nose 2,070 ft/s (630 m/s) 381 ft⋅lbf (517 J)
Test barrel length: 22.75" rifle (higher velocity) and 5.0" pistol (lower velocity)

The .22 TCM (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. The cartridge is primarily used in Rock Island Armory M1911 pistols and the M22 TCM bolt-action rifle.

Initially known as the .22 Micro-Mag, the .22 TCM is conceptually similar to other bottlenecked pistol cartridges, such as the 7.62×25mm Tokarev and the FN 5.7×28mm. The design prioritizes high velocity and reduced recoil by trading bullet mass for speed, making it suitable for various applications

Design and Features

22TCM (left) with 40gr long bullet; 22TCM-9R (right) with 39gr short bullet.

22TCM9R, 9mm Luger, 22TCM, and .38 Super.

Early model RIA Armscor 22TCM M1911 A2, double stack 17 round Para P18 type mag.

The .22 TCM is based on the 5.56×45mm NATO case, shortened to match the overall cartridge length of the .38 Super. This design results in a cartridge approximately 3 mm longer than a standard 9×19mm round. The .22 TCM was specifically engineered for the Rock Island Armory (RIA) M1911 line of pistols, which also supports 9mm barrel swaps.

The magazines used for the .22 TCM are based on the Para-Ordnance P18 pattern, designed for 9mm/.38 Super cartridges, and feature a double-column configuration with a 17-round capacity. Limited production runs of Glock 19 and Glock 17 conversion barrel kits allowed these pistols to be converted to fire .22 TCM by replacing the barrel and recoil spring (rated at 11 lbs). This led to the development of the .22 TCM-9R variant, which uses a shorter bullet and overall cartridge length compatible with Glock and other magazines designed for standard 9mm ammunition.

Performance and Observations

The .22 TCM cartridge features a bottleneck design, which can result in the case "sticking" as it fire-forms to the chamber. This issue can be mitigated by lubricating the chamber with oil. Armscor's bulk factory ammunition has been noted to leave unburned powder residue inside pistol internals, potentially causing reliability issues and producing significant muzzle flash.

The original 40-grain factory-loaded bullet offers a flat shooting trajectory, low recoil, and moderate accuracy in pistols. However, inconsistent accuracy, including occasional flyers and group stringing, has been reported. The cartridge's ballistic performance and overall length have also been critiqued as less than optimal for certain applications.

Armscor 40gr factory ammo vs Speer, and Sierra projectiles in handloads.

Handloading for .22 TCM

Handloaders have refined the performance of the .22 TCM by experimenting with different powders and projectiles to enhance accuracy and reliability. Renowned firearms author John Taffin has published handloading data for the .22 TCM in GUNS Magazine on two occasions: in 2017, focusing on powder loads, and in 2023, addressing the use of various projectiles.

Using Rock Island Armory M1911 pistols with 5-inch barrels, Taffin conducted tests at 20 yards with four-shot groups. The best results were achieved with Hodgdon Lil' Gunpowder (10.5 grains) and Alliant 2400 powder (9.3 grains), both of which are fast-burning pistol powders designed for magnum and high-velocity applications. These powders significantly improved the cartridge's reliability and accuracy.

The Speer .22 caliber (.224") 40-grain Soft Point (SP) projectile was identified as particularly well-suited for the .22 TCM. This combination of optimized powders and projectiles enhanced the cartridge's performance, making it more consistent in both velocity and accuracy.

Factory Ammunition for .22 TCM

Standard factory loads for the .22 TCM include a 40-grain jacketed hollow point (JHP), referred to as the "long slug," and a 39-grain JHP, known as the "9R" or "short slug." Both cartridges use the same .22 TCM case but differ in projectile length.

This distinction has occasionally caused confusion among users and ammunition retailers, with some mistakenly identifying them as separate calibers. Despite the differences in projectile design, both the 40-grain and 39-grain variants can be used interchangeably in .22 TCM firearms, provided they fit within the magazine dimensions of the pistol or rifle being used.

22TCM Factory Ammo Performance

Brand, Bullet, Weight, Type	Velocity FPS	Velocity FPS	Group Size Inches	Group Size Inches
Armscor 40gr HP, older ammo	1,982	2,011	1.75"	1.625"
Armscor 40gr HP, newer ammo	2,044	2,061	0.875"	1.375"

22TCM Handloaded Ammo Performance

Brand, Bullet, Weight, Type	Powder Brand	Charge Grains Weight	Velocity FPS	Group Size Inches
Armscor 40gr HP	Hodgdon Lil Gun	10.5	2,074	1.125"
Armscor 40gr HP	Alliant 2400	9.3	1,942	0.75"

Dimensions

Variants

22TCM vs 22TCM9R overall length, same case different slugs.

22TCM, 22TCM9R, 5.56x24mm with different projectiles.

22TCM Improved

Randall Scott-Key introduced an improved variant of the .22 TCM cartridge, designated as the 5.56×24mm. This modification involved slightly lowering the case shoulder and neck, allowing for the use of a wider range of .224" projectiles. The design enhances reliability by functioning as a reverse piston during the firing process, improving feeding and ejection.

The 5.56×24mm variant is compatible with standard 9mm Glock magazines, further improving its practicality for use in popular firearms. Notably, this variant is fully backwards compatible, capable of being fired from any .22 TCM or .22 TCM-9R chamber.

Scott-Key highlighted the Speer .224" 40-grain Soft Point (SP) projectile as an excellent option for the cartridge, offering reliable performance across various applications.

5.56×24mm vs 22TCM case

5.56×24mm and 22TCM9R in ETS Glock mags

5.56×24mm with Speer 40gr Soft Points, next to 9mm at the back.

Characteristics and Applications of .22 TCM

The .22 TCM, sometimes referred to informally as ".223 Short," was designed as an efficient pistol caliber, achieving velocities of approximately 2,000 feet per second (fps) from a pistol and up to 2,800 fps from a rifle. Its low recoil compared to the 9×19mm Parabellum makes it suitable for training new shooters or for individuals sensitive to recoil.

Weighing less and delivering higher velocities than the 9mm, the .22 TCM is also compared to calibers like the 7.62×25mm Tokarev and FN 5.7×28mm. These characteristics make it viable for lightweight and compact personal defense weapons (PDWs), such as AR-15-style pistols, akin to those conceptualized in the Colt MARS Program.

A notable advantage of the .22 TCM is its cost efficiency, with ammunition prices often being significantly lower than FN 5.7×28mm rounds in the U.S. and other regions. However, citation is needed to support this pricing claim.

In countries with restrictions on military calibers or bore sizes for civilian ownership, the .22 TCM has been considered a potential alternative to commonly prohibited calibers like 9mm, .45 ACP, 5.56×45mm NATO, and 7.62×51mm NATO.

Hunting Applications

The .22 TCM's parent case is derived from the .223 Remington / 5.56×45mm NATO, which are open-source designs. The cartridge has been used successfully in both pistols and bolt-action rifles for hunting varmints, such as coyotes and feral swine.

22TCM AR-15 pistol with 8.5" barrel and DI gas system. 22TCM AR mags, 18 rounds. 40gr factory ammo, and 55gr bullets in handloads. Made by Tim, The AR Guy

22TCM AR-15 magazines designed to take the 40gr factory ammo, holds 18 rounds. Made by Tim, The AR Guy.

22TCM AR-15 mag with handload. Designed to be reliable with longer bullets. Made by Tim, The AR Guy.

2 types of dedicated 22TCM AR-15 mags. Note the different length followers and built in feed ramps. Designed for either the 40gr factory ammo, or longer handloads. More reliable compared to 9mm conversion mags as 22TCM is slightly longer overall length. Hold 18 rounds but can be extended. Made by Tim, The AR Guy.

See also

• .22 Spitfire
• .221 Remington Fireball, a similar necked .22 centerfire round
• 5.56×21mm PINDAD, cut down 5.56×45mm
• .224 Boz
• 5mm RRM (5.2x26mm)
• 7.62×25mm Tokarev
• 7.63×25mm Mauser
• 7.65×21mm Parabellum
• 7.65×25mm Borchardt
• FN 5.7×28mm