I picked up my PSA dedicated Glock AR lower and immediately topped it off with a 22 TCM Pistol
Wait a minute..... I thought I said that wasn't a good idea? Yes, that is what I said, and I still mean it. Don't try this at home. This was a controlled test only to collect some data. I used a Glock 9x19 mag and loaded up some special TCM rounds to 1.18" oal and a light charge of 2400 powder. All I wanted to do was test fit and function and I'm pleased to report that things worked well and its a nice plinking round, very similar to our 22 Uzi.
I'll state this one more time: Stock TCM rounds are much too hot for the blow back AR and I've heard reports of case head separations even with the 9R rounds. Besides, why handicap yourself with blowback when this is a great gas gun!
My next test will be with the Glock lower will be the 30 Luger
Could 22 tcm be made safe in a blowback with a heavy buffer spring in something like a sterling/sten carbine or my current dream a kel tec sub 2000? Also I need to order some of the modified m1 carbine mags for 22tcm... do you have any to sell?
Hey Mtndrew, welcome to the forum! I'm trying to get more mags set up and working on the followers. We are doing more testing with blow back operation and it would be ideal in an original PPs-43. The TCM has to get into the 1.28" mag size, for stock bullets and 1.38" for real bullets. Our initial testing for the TCM did not work well with a blow back as it was worse than the tokarev blow backs even with super heavy buffers. The gas guns are just so much smoother. We are looking at our MODRAB set ups, but just not enough time at the shop right now.
Thanks for the welcome. You are a hard man to get ahold of. Let me know when followers or magazines are available. I'm going to continue to try and modify my m1 carbine magazines with my dremel and soldering iron. So far none of my ideas have not panned out. Bending the front of the feed lips did not work out.... now I'm looking at soldering an extended feed ramp to the front of the magazine and blocking off the front half of the magazine with pipe and a hole in the follower.... it's hard to describe.
I already have one of your 22 TCM barrels, (which runs like a champ by the way) and wondered if you planned on doing any longer and a little heavier barrels for the AR varmint hunter? I can't go for anything right now but I wanted to check for future reference.
TCM 9R UPDATE: Do not try this at home! Just got a report in and the 9R is getting split and stuck cases in the blow back set up. Reduced load TCMs run fine. Mr F is doing some measurements and sending back data. Again, the locked breech 1911 / Glock set ups are totally different than the straight blow back AR (22 rimfire) set up.
On the subject, we are testing some TCM subsonic loads with surplus SS109 bullets and 4.8 gr of 2400 powder in our DI carbine. Velocity is just under 1100 fps with the bullets seated into the cannalure. Rounds eject just fine from our new M1 carbine mags, but I can't pick up another round yet. Tok mag set up works fine with the rounds a bit closer to the chamber, but the 1.38" oal is too short for the 1.5+" OAL of the SS109 loads. I don't have all my spring / buffer combo's here, but we'll keep playing to see what we can make happen with some faster and slower powders.
Did a bunch of sub playing yesterday with our standard 22 TCM carbine set up looking for a reliable sub sonic load. Using the 62gr surplus SS109's as a base, they are too long to run in the Tokarev mag set ups. Our new M1 Carbine mag set ups work with the right load as I'll share more later on. I was also limited on bullet selection as all of my heavy 22 stuff was left at the shop. Again, running the TCM in a blow back AR is not recommended. It is way too easy to get yourself in trouble. The TCM runs very well in DI and the mags are getting worked out so there is no reason to even try the blowbacks. I've done some basic loads with powders from bullseye to Lil Gun for sub loads. Starting with 2400 we got the rounds to eject fine, but would not pick up another rounds. Going to a faster powder didn't help so we went slower with what I had on hand, AR Comp with is similar to Varget in burning rate. Working around we settled at 8.1 gr with the 109's seated in the cannalure with a moderate crimp put us solidly in the 1020-1040 fps range. The best part is cycling was 100% and locked back the bolt with the BHO feature of the new mag set ups. Heavier bullets should work fine with small powder weight charges. Heavier bullets should also work with smaller charges of faster powders to get the bolt to lock back. I don't know what twist rates are going to end up being best, but the faster the better. I'll get something together when I get a chance.
Knocking out some TCM barrel and its nice to be back at the shop. For those of you who have called and not gotten a response.... my apologies. As you know, over half the call are robo or google or credit card crap and they guys just stopped answering the phone. Worked up a load last month on request: guy wanted a 75gr sub sonic load with super fast twist barrel. Worked up some loads with the usual suspect powders, but wanted something that would cycle the action in our TCM set up. Switched over to AR Comp powder and got the loads into a steady 1000 fps beat. Twist was way too slow for the bullets, so thats whats on the lathe right now, a 1:7 twist pistol barrel for the TCM sub testing! Oh, we are using our new M1 Carbine dedicated mag set ups with it. The BHO feature is soooo nice....
TCM testing to be done this trip: my std 1:12 carbine New 1:14 SS 18" bull barrel upper New 1:7 for sub work. Got two new mag set ups going and will work on follower data with these uppers to see how things go.
We did a fast twist barrel to see if the 62gr SS109s would stabilize at subsonic velocities and testing off hand at 25 yds show much improvement over the 1:12 barrels. You can make out the 5 shot group of 22 cal holes
Knock 2 rounds off the bench at 100 yards of the 62gr sub loads with the fast barrel. Only 104 degs out so didn't stay out long. Looks like more testing needs to be done but not bad...
Assembled my personal 18" SS TCM this weekend but not enough time to test. The SS barrel and nickel BCG set up really sets it off. Got new TCM tooling in and running another batch of barrels in SS and CM. Will get pics up as soon as we get them cleaned up! On the sub side, rounded up my 75 gr bullets and will get some more sub stuff done when I get a chance.