Pics as promised. This is a Thompson Machine Poseidon on it, come a week from Friday I will have pics of a Thompson Machine Isis9 on it!!!
As long as I am happy with the performance of the threads, we will be offering this thread pattern on factory guns for $75otd with about a 2 week turn around.
I have shot about 200 rounds through it since doing the threading and haven't had any problems. When I threaded it I left .100" between the slide and the start of the threading. This only gives me .250" worth of threads but it torques down good and tight and hasn't loosened up on me yet. I haven't gotten the 10# recoil spring for it I was told would make it run becuase it's backordered from midway but when it shows up I'll post and update.
I'm not sure how much of a dif it would make but mine is 1/2-36 so I may only have .250 threaded but I get 9 full threads in that .250 compared to 7 with 1/2-28. I doubt either is better, I always figured colt threaded their 9mm ARs in 1/2-36 so muzzle devices wouldn't get swapped and cuase any trouble.
After reading the thing about needing .400" I just had to measure my carry 92FS and found that there is only .328" of barrel ahead of the slide.
I am trying to figure why the pistol fails to cycle with the can in place, but can't come up with anything obvious. As stated earlier, I would try a lighter recoil spring, and try to be very aware on how hard the slide is slamming back with the light spring versus the standard. You don't want to destroy the frame to solve an issue that might be the can not being proper for the 92FS. Just a thought and my 2 cents worth.