.22 TCM Load Data
March 02, 2015
Because the .22 TCM is a proprietary cartridge, not a SAAMI cartridge, and no published load data and information exists, handloading it is much like working with a wildcat.
The .22 TCM is a short, bottlenecked case with case head dimensions that are almost identical to the .223 Remington. It is a proprietary cartridge produced by Armscor, and it was designed by Frederick Craig (www.atomitronx.com) to be fired in a Model 1911 pistol. Topped with a 40-grain JHP bullet, it will deliver approximately 2,000 fps from a 5-inch barrel. For more about the cartridge's heritage and to see what it can do out of a 22-inch-barreled bolt-action rifle, see the article beginning on page 36 of this magazine.
Because the .22 TCM is not a SAAMI standard cartridge, the component suppliers have not developed handload data specifically applicable for reloading the .22 TCM. They haven't produced components specifically for it, either.
So what you're about to read is strictly a summary of my experiences developing safe handloads for this round. I've treated it as essentially another wildcat cartridge. I began the project with several hundred once-fired cases I'd picked up at one of the InterMedia Outdoors editorial roundtables where I first fired a Rock Island Armory 1911 in .22 TCM.
Getting Started Reloading .22 TCM
The sole Armscor factory load contains about 10 grains of a noncanister propellant and a 40-grain JHP bullet made by Armscor. During my conversations with Craig, he suggested that W296 or H110 might be applicable, and he cautioned that loads consisting of a powder with a faster burn rate could be unsafe. The only bullets he noted as possibly being compatible with the round's overall length constraint (it has to fit in the Model 1911's magazine) were the Hornady 35-grain V-Max and the Hornady 45-grain JHP bullet specifically configured for the .218 Bee.
When little or no lab-tested load data is available for a cartridge, I try to find a comparable existing cartridge based on caliber, case capacity, and operating pressure. The .22 TCM has been compared to the 5.7x28 cartridge, but I determined that the .22 Hornet seems to meet all three criteria. The maximum average pressures and case capacities of the .22 TCM and the .22 Hornet are about the same, and the Hornet is typically loaded with 30- to 45-grain bullets.
I measured case capacities and found them to be almost identical. In fact, the TCM case held a few tenths more water than the Hornet case (Winchester brand). Of course, the two cartridges are shaped completely differently. The Hornet case is tall and skinny with essentially no shoulder compared to the relatively short, fat TCM case with its distinctly bottleneck shape. I decided I could safely use the Hornet's starting load recipes and work up from there.
I tried Barnes's 30-grain Varmint Grenade, Speer's 33-grain TNT, Hornady's 35-grain V-Max, and Hornady's 45-grain JHP Bee bullet. Based on reviewing various burn-rate charts, I decided on Lil'Gun, H110, W296, IMR 4227, Accurate 1680, VihtaVuori N110, and Alliant 300-MP powders. I based my starting charges on the results I had obtained by pulling bullets of some factory ammo and weighing the powder.
I had to determine just how long to seat the various bullets so they would still reliably fit and feed from the magazine, so I assembled a number of inert dummy rounds. I discovered the TCM's 17-round, staggered magazine would reliably function with the bullets seated out to 1.275 inches, plus or minus a few thousandths, depending on the specific nose shape.
Prepping the cases involved tumbling the brass, brushing the inside of each case neck, applying Redding Imperial wax before resizing, resizing the brass with a Hornady sizer die, wiping each piece to remove most of the case lube, cleaning and uniforming the primer pockets, and tumbling the cases again to thoroughly clean them before loading.
Because the .22 TCM does not require crimping the bullets in place, I only had to assure the case lengths were not too long. Since there aren't any official dimensional specifications, I measured a few factory rounds and set max OAL at 1.030 inches. I didn't trim any brass until after the second reload cycle.
When reloading a small-capacity, high-intensity cartridge, a few tenths of a grain of powder will significantly affect ballistic performance. Since I wanted to accurately assess the difference in performance between, say, 10.0, 10.2, and 10.4 grains of propellant, I weighed each charge.
I seated all of the bullets to 1.270 inches, +/- 0.005 inch. Case neck tension felt quite adequate to securely hold the bullet. Often the powder charge was compressed so the bullet was also supported from the base. The 35-grain V-Max handloads looked somewhat odd because the initial ogive ended up a bit below the case mouth, but if there was enough juice, the test loads fed and ejected without a hitch.
Handloading .22 TCM: The Results
During the first range session, I fired 20 rounds of factory ammo to check the gun function and establish a velocity baseline. I had also pulled a few bullets from factory rounds, weighed the charges, and reloaded them, substituting my selected component bullets. I fired those next to record velocities and to see if the gun functioned properly.
Factory .22 TCM loads create a lot of muzzle blast and flash, but recoil is actually mild. As for my handloads, well, I quickly noticed that loads with the lighter bullets didn't always provide enough impulse to reliably cycle the action. I eventually abandoned the 30-grain bullet. I had one propellant (VihtaVuori N120) that didn't cause much muzzle flash at all, but it was a bit too slow to yield optimum performance.
I fired nearly 100 five-shot groups, including the factory load. Based on that experience, I found W296 and 300-MP to be the most suitable propellants. Lil'Gun worked well with the 45-grain Bee bullet. Unfortunately, my older sample of H110 did not deliver the same results as the fresh bottle of W296. This should remind you that different lots of the same propellant often exhibit slightly different burn rates. That variable alone can push pressures to unsafe levels in a high-performance cartridge like the .22 TCM.
The handload data chart lists only those handloads that I considered to provide safe and acceptable performance. Without extensive lab tests to measure actual chamber pressures, all one can do is be extra careful. The factory load delivers 2,000 fps, and meeting that performance level is a challenge, much less trying to beat it. If you just have to have more velocity, try the two lighter-weight bullets. Adding more powder can get you into trouble quickly.