Going after the TCM today and will report back when I can test. Both of these will be BB version per the customers request. If I have time I'll do another DI or Piston set up. The brass looks great but with a huge burr at the neck, inside and out that will have to be dealt with first. The necks look to be on the thick side, by design I am sure for ease of mfg. .015" +
Tim, Need some info -- will you be testing the blowbacks first with maybe a DI or piston version later or do you have enough blanks to make a DI/Piston version now. I think the original version of the 22 TCM allowed for the thicker necks so no neck turning was required. You going to try a regular 9mm blowback bolt in the BB versions? What magazine -- your M1 carbine mags with adapter? Love to see somebody else get one off the ground and in two types of operation.
Doing blow backs first with 9mm bolts. Barrels are done, have to get my 22x9 fire forming plan together. Then I'll load up some squib TCM stuff to test in blow back. Learned my lesson with the 22 RE Yes, I am assuming the brass is fine and the chamber will work as cut. Yes, I have a couple extra blanks here..... Time? don't know about that yet, opportunity has knocked again.....
Loaded up some 3g bullseye loads for testing in the tcm blow back. Tok mags set too level and need to work on barrel breach face if they are going to feed from them as we can't get the ramps any higher. Uzi mags will feed one at a time so I"ll dig out one of my old Tok "ramped" mags for testing.
Ran the TCM blow back pistol yesterday at the range using Tok mags and our blow back adapter. Feed and function was 100%. Load was 6gr of H110 and the TCM 40gr JFN bullet. No chrono so we just let em fly. Will put the carbine together and then work on a DI version.
I found my 30 round M1 carbine magazine that I used to test the 22 TCM case with 40 grain bullets. for some reason one bullet was set to just at the Ogive and the other was set out long. The shorter one may be too short since the one set out long looks perfect for the carbine magazine and measures 1.600" overall. The problem I have now is I'm not sure of the bullet used in the long cartridges -- they are moly coated and I swear they look heavier than 40gr -- like maybe 50gr but I don't have the box they came in anymore.
Since I don't have a 22 TCM barrel (yet) I decided to resize a few TCM cases to the same length as the 22 Reed Express. The cases were already necked to 22 caliber so I just pushed the shoulder back a bit and trimmed the neck and had to turn the necks. The work was a bit of a pain but not having to form the necks down like with 7.62X25 cases was a real time saver. I'm pretty sure the brass will hold up fine with some of my healthier 22 RE loads but I have to remember to change back to a standard AR bolt or the firing pin strike on the primer is a little off center which I figure means the cartridge is a bit off center in the chamber when I'm trying to fire form these cases. I had a 22 Reed Express case gauge made many years ago and the reformed TCM cases fit perfect.
I know you are up to your ears with work but I hope at some point you get a chance to make up a 22 TCM barrel and try the carbine mags with one of your carbine mag adapters with the TCM cartridges. If the carbine mags work and can be loaded to capacity, that setup would make a nice little varmint field rifle.
Edit to add: I just ran some of the reformed brass through the 22 Reed Express and it worked super. and I used the M1 carbine magazine since the cartridges where using 40gr V-max bullets with a COL of 1.49" and would not be usable in PPS-43 mags.
2nd Edit to add: The picture below is the reformed TCM brass on the left to the 22 Reed Express size. The cartridge case has not been fire formed yet but you can get the slight difference in size. With the original 7.62X25 brass formed to 22RE I could get 3200fps using the Barmes 30gr Varmint Grenade out of a 16" DI AR barrel and I believe these reformed cases should come close if not equal the 7.62X25 reformed cases.
I wish I had an idea as to what I could get out of the actual 22 TCM case in a DI AR-15 but I guess I'll have to wait till I can afford a custom barrel.
The picture below is the 17 Reed Express on the left next to the 22 Reed Express. The 17RE is good for 3800FPS if loaded hot and is based on the 7.62X25 Tok cartridge case.
Last Edit: Jul 2, 2015 18:08:09 GMT -5 by 22boomer