.22 TCM Cartridge Review

.22 TCM Cartridge Review

Previously known as the .22 Micromag

A few years back, Fred Craig of Pahrump, Nevada, developed a cartridge called the .22 Micromag. When it was adopted later by Armscor, the name was changed to .22 TCM - an acronym for Tuason (for Martin Tuason, Armscor president), Craig, Micromag. It is the latest of several factory-loaded .22 caliber centerfire cartridges originally developed for handguns.


Remington got the bandwagon rolling back in 1961 by necking down the .357 Magnum for .222-inch bullets and calling the result the .22 Jet. It was introduced in the ill-fated S&W Model 53 revolver. Two years later, Remington struck again with the .221 Fireball, a cartridge on the shortened .222 Rem. case designed for the equally new XP-100 pistol. Around about the same time, the Russians came up with the 5.45x18 Soviet for the compact PSM autoloading pistol. And, of course, we have the 5.8x28 FN in the FN Five-Seven autoloader.

Then in 2012 came the .22 TCM in a wide-body 1911 pistol from Rock Island Armory. The capacity of its double-stack magazine is 17 rounds. Also included with the gun is a barrel and recoil spring for converting it to 9mm Luger. The magazine works with both cartridges.

.22 TCM Cartridge Review
Handloaders can currently find .22 TCM dies from Hornady and unprimed cases from Armscor.

The .22 TCM is the fifth factory-loaded .22 caliber offspring of the 1950-vintage .222 Rem. The others are the .222 Rem. Mag., .223 Rem., .221 Fireball and the European-designed 5.6x50 Mag. The new cartridge is also the shortest. That title did belong to the .221 Fireball, but its 1.400-inch case makes the 1.022-inch case of the .22 TCM the Mickey Rooney of the .222 Rem. family of cartridges.

Maximum overall cartridge length of the .22 TCM is 1.275 inches, same as for the .45 ACP. Loaded with a Small Pistol primer and a 40-grain jacketed hollowpoint bullet, the velocity rating from a five-inch barrel is 1,875 fps. That's no brag as some lots of ammunition have exceeded 1,900 fps. Economical to shoot as factory ammo goes, I have seen it advertised by Cheaper Than Dirt and other companies at less than $20 for a box of 50.


The .22 TCM chambering is now available in a Rock Island Armory rifle called the Model TCM. Advertised velocity of the Armscor ammunition from its 22-inch barrel is 2,800 fps. The politically correct among us love to bounce around the term "value priced" when describing an inexpensive firearm, but where I come from a rifle like the Model TCM still goes by the name of "knockabout." And I don't mean to be derogatory because some of the best buys in the rifles of yesteryear have worn that moniker.

The .22 TCM has a turnbolt action that, according to an Armscor official, was originally designed for the Armscor Model 1500 rifle in .22 WMR. Changing the firing pin to centerfire along with making the receiver, bolt and barrel of stronger steel (Type 4140) as well as more stringent inspection processes resulted in a rifle capable of handling the .22 TCM cartridge. The action was also modified to accept the double-stack magazine of the pistol.

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The .22 TCM cartridge, chambered in the Rock Island Armory TCM rifle, makes a strong case as an effective varmint round.

The design of the bolt is not identical to the bolt of the Anschutz 1730/1740 action, which is used for rifles in .22 Hornet and .222 Rem., but they are similar. The bolts of both rifles consist of a non-rotating front section containing the extractor, along with a rotating rear section containing a single locking lug. When the bolt is rotated to its locked position, the lug engages a shoulder in the floor of the receiver. But their breech-locking designs are taken one step further. In both actions, the root of the bolt handle bears on the rear edge of its cutout in the receiver tang and in doing so considerably increases resistance against cartridge back-thrust during firing. The Anschutz was also originally intended for the .22 LR and later modified to handle centerfire cartridges.


When the firing pin of the .22 TCM is in the cocked position, its rear end protrudes in easy view from the rear of the bolt shroud. There can be some bolt travel binding, but a light film of oil spread over its surface every 100 rounds or so keeps it running smoothly. Bolt lift is made easy by an occasional dab of grease on the firing pin cocking ramp of the cocking piece. The rear surfaces of the locking lug and the bolt handle where it bears on the receiver should also be kept lubricated.

Since the action is designed for an extremely short cartridge, bolt throw is only a hair over 1.75 inches. And while the spring-loaded extractor at the face of the bolt seems quite delicate for a centerfire rifle, yanking hundreds of spent cases from a powder-fouled chamber presented no problem for it. Even so, should a case stick due to excessively high chamber pressures, you would not want to pound on the bolt handle. A fixed-blade ejector rests on the floor of the receiver bridge. The bolt release located on the left-hand side of the receiver bridge works nicely and is within easy reach of a thumb.

.22 TCM Cartridge Comparison
Cartridges (left to right): .22 TCM, .22 Hornet, 5.7x28 FN, .221 Rem. Fireball, .22 Rem. Jet. Case capacity of the .22 TCM is close to the Hornet's and about 11 percent greater than the FN. Among the author's bullet choices for handloading were the Hornady 35-grain V-Max (far l.) and the Sierra 40-grain Hornet, shown alongside the factory 22-grain softpoint.

A two-position, trigger-locking safety lever located at the right-hand side of the receiver tang operates smoothly, but there are no spring-loaded ball detents to prevent it from being inadvertently shifted from the Safe and Fire positions. At 5.5 pounds, trigger pull is a bit heavy for a varmint rifle, but otherwise the quality is darned good for a rifle in its price range. No creep that I could detect, and while there was some overtravel, the break was crisp.

The magazine holds five rounds, but for those who prefer to drop 17 varmints between reloads, as I mentioned the double-stack .22 TCM magazine from the Rock Island Armory pistol works in the rifle. The five-round magazine is not easy to load, especially the last round. If the rifle were mine and I intended to shoot it a lot, I would use the 17-round magazine as a 10-rounder because it is so much easier to load.

The receiver is grooved for scope mounting, but due to its rounded top, you can't just grab any rings and expect them to work. I first tried Talley and found them to be a no-go. When a friend at Armscor sent a pair of Sun Optics rings designed to fit dovetails ranging from 9.5 to 13mm, I was in business. A 3-9X scope from the same company also arrived, but I desired more magnification and opted for a Burris 6.5-20X Fullfield II instead. A screw in the top of the receiver at the forward end of its grooved section serves as a stop for the front scope ring.

The medium-heavy, button-rifled .22 TCM barrel is 22 inches long, measures 0.750 inch at the muzzle and has a rifling twist rate of 1:16. That twist has been standard for the .22 Hornet from the day it was introduced during the 1930s. It usually won't stabilize anything much longer than the 45-grain Hornet bullets available from Sierra, Hornady and Speer, which is just fine since heavier bullets cannot be pushed fast enough for the explosive expansion needed on varmints such as prairie dogs and flickertails. The barrel is threaded and screwed into the receiver.

.22 TCM Cartridge Magazine Options
Magazine options include a supplied five-rounder and also the 17-round mag Rock Island Armory uses in its TCM-chambered 1911. Simpson found the five-rounder hard to load and would opt for the larger-capacity mag downloaded to 10.

The stock appears to be stained birch. Other features include adequate checkering coverage and a fore-end properly shaped for shooting over a sandbag. Increasing the price just enough to include sling swivels would not be a bad idea. The stock is removed from the barreled action by turning out the usual hex-head bolts at tang and receiver, but since the magazine catch button interferes with stock removal, it too has to be removed. Most who own 1911 pistols will find this easy to do.

The lack of pressure-tested load data for the .22 TCM has not deterred handloaders. Because case capacity is close to that of the .22 Hornet, starting loads listed in various reloading manuals are commonly used. Gross water capacity of the Armscor cases on my loading bench is 0.5 grain more than for the .22 Hornet (Winchester brass) and 1.3 grains more than for the 5.7x28 FN case.

For a while, Fred Craig sold unprimed cases and custom-made dies for the .22 TCM. Hornady is now making the reloading dies as well. Also available are Armscor unprimed cases for $19 per 100 or $184 per 1,000.

Craig recommended the use of W296 and H110 propellants in the .22 TCM. Other .22 Hornet powders, such as Hodgdon Lil'Gun, Ramshot Enforcer, Accurate 1680 and Alliant Power Pro 300-MP, may eventually prove to be equally good candidates. The Western Powders website will likely be the first source for load data, but I am told it is still months away.

Armscor sent plenty of ammo, so I began testing the .22 TCM rifle's accuracy by shooting 10 five-shot groups at 100 yards. Group sizes ranged from 2.28 to 4.30 inches for an overall average of 3.08 inches. Case extraction was a bit sticky, and that interfered with ejection—with some cases having to be manually plucked from the ejection port. There were also three misfires.

22-cartridge-tcm-review-5

Figuring the .22 TCM rifle was capable of better accuracy, I turned to handloading. For load development I used the Federal 205M Small Rifle primer and three bullets: Speer 33-grain Hornet TNT HP, Hornady 35-grain V-Max and the Sierra 40-grain Hornet.

As I discovered, the Hornady and Sierra bullets are not suitable if the rifle is to be used as a repeater. In order for cartridges to fit into the magazine, overall length has to be held close to the 1.250 inches of Armscor factory ammunition. The ogive of the Armscor bullet is quite short, and that results in a short length. It measures 0.470 inch compared to 0.485 and 0.515 inch respectively for the Sierra and Hornady bullets.

Seating the Sierra and Hornady bullets to the same overall cartridge length as Armscor factory ammo positions the mouth of the case far out on their ogives, reducing surface area contact between their full-diameter shanks and the neck of the case to less than 100 percent. The chamber throat in the rifle was long enough to allow bullets to be seated out farther than factory length and still remain shy of contact with the rifling. That enabled me to seat the Sierra and Hornady bullets to respective overall cartridge lengths of 1.350 and 1.375 inches. Doing so required shooting the .22 TCM single shot, but when bumping off prairie dogs with a bolt-action rifle, I seldom use its magazine anyhow.

Measuring only 0.405 inch long, the 33-grain Speer bullet is shorter than the Armscor 40-grain bullet and can be loaded to an overall cartridge length that's compatible with the magazine of the rifle.

Hodgdon's Annual Manual lists starting charges of W296 in the .22 Hornet as 11.0 grains for the Hornady 35-grain V-Max and 10.0 grains with the 40-grain Speer for respective velocities of 2,805 and 2,569 fps. Also listed are velocities of 3,060 and 2,795 fps for maximum charges of that propellant. Having no Speer bullets of that weight on hand, I started with 9.8 grains behind the 40-grain Sierra and 11.0 grains with the 35-grain Hornady. Respective velocities with those starting loads in the Rock Island Armory rifle were 2,479 and 2,774 fps.

tcm-review-22-cartridge-6

Increasing the charges behind the two bullets in 0.2-grain increments, I stopped adding powder behind the 40-grain bullet once its velocity closely matched that of the Armscor factory load. According to Hodgdon, when 35- and 40-grain bullets are loaded to the same chamber pressure in the .22 Hornet, the lighter bullet is 265 fps faster. I stopped increasing the charge of W296 behind the 33-grain Speer and 35-grain Hornady bullets when their speeds exceeded the velocity of the 40-grain Sierra by about 250 to 260 fps.

Just as had happened with Armscor factory .22 TCM, case extraction was a bit sticky with those loads. Reducing powder charges for a reduction in velocity of 75 to 100 fps transformed the .22 TCM into a different rifle. Case extraction and ejection became silky smooth, and accuracy with the Hornady and Sierra bullets improved dramatically.

While firing close to 300 rounds of handloaded ammunition, I experienced seven misfires with the Federal 205 Small Rifle primer. Since the .22 TCM was originally developed for 1911 pistols, it used a Small Pistol primer, and I assume that's what Armscor factory ammo has.

Thinking a switch to a Small Pistol primer would eliminate the misfires, I tried the CCI 500 and received poor results. Misfires actually increased, velocity spread just about doubled, accuracy got worse and cases emerged from the chamber with their exteriors heavily coated with powder fouling. Other Small Pistol primers might work better, and the CCI 500 might work better with other powders, but it is not the primer to use with W296 in the .22 TCM. I'll stick with the Federal 205M until something better comes along.

The Rock Island Armory Model .22 TCM had a two-digit serial number, and I have been in this business long enough to know that early production firearms made by any company can and occasionally do escape the factory with a gremlin or two lurking inside. Company officials have been made aware of the misfire problem, and I'm sure the issue has been resolved in rifles built after the one I shot.

The number of Lee and Hornady reloading dies and Armscor unprimed cases sold since the introduction of the .22 TCM in 2012 indicate many who own Rock Island Armory 1911 pistols chambered for the cartridge are handloading it successfully. The same will now apply to the rifle. But due to the litigious society we live in, I have included in this report only the starting loads used with various bullets. That's all that will be needed by experienced handloaders who own chronographs and know what sticky case extraction means. The inexperienced would be wise to stick with factory loads until pressure-tested data for the .22 TCM becomes available.

The very first varmint rifle I shot as a youngster was a Savage 219 in .22 Hornet. I have long had a fondness for the cartridge and presently own five rifles chambered for it. But I will have to admit, a stronger case makes the .22 TCM an even better varmint cartridge. What we have here is the modern version of an old favorite.

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