Received this from Mike Bellm if its of any interest....
Newsletter: The .22 TCM & Smallish .22s
One thing that reigns apparent working with the TC system is that all the flexibility of their interchangeable barrel systems lends itself well to accommodating folks who have a strong interest in moderate types of rounds. Ie, not everyone thrives on smashing energy, ultra velocity, and the quest for laser-like trajectories.
Many are like me who appreciate the virtues of relatively pipsqueak rounds.
A number of Newsletters back I mentioned the .22 TCM, which was originated as a 2,000 fps round for 1911 type handguns, ala the 5.7x28, and legitimized as a production item by Armscor who now has factory ammo readily available at a refreshing price in this day and age, $25/50 or less from the discount houses.
At the time of the Newsletter I was eyeballing the .22 TCM, which stands for Tuason/Criag Micromagnum, closely as a potential round for the TC break open systems and noting how similar it is in capacity to one of my long standing favorite Contender rounds, the .22 K-Hornet. Comments on various forums alluded to applications and potentials in rifle length barrels, which fanned the flames of curiosity.
So what does this all have to do with TC guns?
Hang on........
The .22 TCM has a water capacity listed on
ammoguide.com/cgi-bin/ai.cgi?sn=phGKpSLbpQ&catid=834as 17.3 gr. They list the .22 K-Hornet as 15.5 gr. That is something just under a 10% increase in capacity.
With much more of a backlog of work than I wanted at the time and no time to explore the .22 TCM further, it remained on the back burner.
Then, EUREKA!
At the SHOT Show back in January I had the good pleasure of meeting Martin Tuason himself...... after first fondling Armscor's beautiful , trim little bolt action rifle chambered in, you guessed it, .22 TCM AND with believable advertising claims of 3,000 fps with their 40 gr. factory ammo. I then got to meet Martin Tuason himself. Martin is an incredible young man following in his father's footsteps leading a very accomplished and aggressive firearms and ammunition company, Armscor, which in turn owns Rock Island Armory, famous for 1911 type semi-auto pistols.
The link to the bolt action rifle was too long to paste here, so go to:
us.armscor.comand troll around for their .22 TCM bolt action rifle, due to be available about June this year they said.
The .22 TCM is basically a 9mm Luger case necked down to .22 and fits the "short fat" concept exemplified by the various "short mags" that are all the rage, but in miniature.
I don't have any of the brass in hand to compare with the very thin .22 Hornet brass, but if the TCM case wall is any thicker than the Hornet's, it should stand up to higher pressures and repeated reloading better than the Hornet does. This in turn suggests one can exceed the advertised 3,000 fps.
That the TCM's pressures have to be compatible with semi-auto pistols, it implies that in the stronger TC guns, INCLUDING the Contender, we should be able to handload it to even higher velocity levels. We'll see how this all develops, but for now $25/50 for factory ammo at 3,000 fps from a rifle length barrel is more than reason enough to grind or buy a reamer right away!
We have a quantity of unchambered, 24" blued Bergara Encore barrels on hand right now, ready to chamber for the TCM or any of the other smallish .22s like .22 Hornet, .22 K-Hornet, .218 Mashburn Bee, etc., or larger of course.
The matter of twist rate.......
Experience has shown that the matter of twist rate is over rated in many instances. Eons past, I worked with Blaine Eddy, now deceased I understand, experimenting with successively larger chambers in the same .224" 10" twist Contender barrel, starting out with .22 LR, rechambering then to .22 rimfire mag, working on up to .223 Rem. and doing accuracy testing with each successive chamber with an extreme range of bullet weights in the .223 Rem. chamber.
Blaine found that every weight from the short little Sierra 40 gr. hollow point through 69 gr. Hornady boat tail match bullets all shot under an inch at 100 yards. While the heavier bullets shot somewhat tighter groups, accuracy with the 40 gr. bullet was excellent in spite of the fast twist rate.
There are other extreme examples of over spinning bullets I can cite..... such as 3/4" groups from short, squat .256 Win. 60 gr. bullets fired at 4,000 fps from a .257 Roberts Improved also with a 1-10" twist rate.
In short, yes, slower twist rates with light bullets do generally give somewhat better accuracy, but a properly throated and crowned barrel spinning a bullet much faster than necessary will still give excellent accuracy. The object is to not distort the bullet in an oversized diameter throat or one that is badly misaligned with the bore. Keeping it in balance is the key so that the effects of high rpm's do not result in poor accuracy.
Would I pick up a barrel with a slower twist for 40 gr. bullets, given a choice? Yes, but 1-10" twist for the Encore is all we have to work with for the Encore, and I would not hesitate one bit to shoot 40 gr. bullets with the expectation of excellent accuracy.
For the Contender platform, any of the .22 LR and .22 Mag. factory barrels can be rechambered to the .22 TCM.... or any of the other smallish .22s mentioned above.
Most of the vintages of .22 LR barrels made by TC have a somewhat smaller groove diameter, .222 to .223", BUT do have a 1-15" twist which has proven itself very well when rechambered to Hornet & Bee types, .221 Fireball, and .222 Rem. when the lighter/shorter bullets up through most of the 50 gr. flat based bullets are used. I, personally, and customers have gotten excellent accuracy with both .223" diameter "Hornet" bullets as well as .224" bullets in the rechambered rimfire barrels.
My K-Hornet barrel has a .223" groove diameter and simply loves the .224" Sierra flat base hollow point. The bottom line is that the smaller groove diameter is not an issue. In fact, I much prefer a groove diameter slightly undersize as opposed to anything more than about a half thous. over bullet diameter.
If you want one of the blued Encore barrels chambered in .22 TCM or any of the other smaller .22s, reply to this email for .pdf copy of the price list and ordering information.
Emphasis right now is on the Bergara Encore barrels on hand, but I'll also rechamber Contender barrels.
Spring and summer varmint shooting is just around the corner, and at $25/50 for factory ammo you can skip reloading, shoot to your heart's content, and still have time to get the yard cleaned up.
All the best,
Mike Bellm
