We get a lot of orders for the 22 TCM 9R for use on Glock Lowers…… and a lot of disappointment from the caller when I tell them, ” You can’t do that.”
But the 5.7×28 works in blow back… yes it does.
The factory TCM brass is soft. If you reload it you will find out how soft it is, and I believe that is a contributing factor to the case head separations. Therefore, we don’t build blow back TCM’s. The DI version works great, but you need a magazine to feed it.
We have been working with the TCM for years and our first tests were for a customer wanting to build Blow Back systems for the TCM. Of course we built test units and quickly blew things up with multiple case head separations and worse. We told the customer, and they didn’t care, they wanted the barrels, they could fix it. They called back and said the TCM’s were blowing up, what was wrong with our barrels……
The Glock Lower: You can make a Glock lower cycle with a DI upper, but it takes cutting the BCG and some other mods. In the name of science, we have done that and have a hand cycling upper, but do not have a running DI/Glock version. It will run, but not 100% as there are still geometry issues, slop in the magwell, and excessive drag. We made a custom mag release to modify the magazine location and are getting better results. Just don’t have enough 9R ammo to test fully…
TCM mag Lower: So also in the name of science and BRD, we cut a Glock Lower to accept a std TCM mag. Again, you need to cut the BCG accordingly and other mods. We are hoping to test that unit this weekend (along with the Glock version)
I hate to say this, but the TCM ran 100% on our test upper. I took a new Upper and put it on the TCM lower for testing to see if it would make a difference….
and again,,,, it ran 100%. I’ll load up some more ammo for testing and figure out pricing for cutting parts and offer a complete kit – the lower. I don’t plan on getting into the lower business, but the mod is straight forward.