I just finished 1000 rounds today. My take down screw is still tight. I have five magazines and I got the barrel as hot as I could.
There is SOMETHING DIFFERENT from my SW22 to the ones who have problems.

Here is my method...
Clean and lubricate the take down screw using Mass Air Flow Sensor Cleaner to strip the screw and receiver threads clean and use M Pro 7 gun oil to lube the threads. No Loctite.
Tighten to 50 in./lbs. although the take down screw stayed tight at 40 in./lbs. through 500 rounds.
The shoulder of my cap screw is square and flat to the shank.
The resting place for the shoulder of the screw cap inside the frame is clean and flat. No shiny surface in there.
With the frame removed from the slide and barrel, my take down screw goes all the way into the threaded piece in the barrel until the threads end where the unthreaded shank starts.
The gap from the screw cap shoulder to the threaded piece in the barrel is less than the bulkhead in the frame. That means my screw isn't bottoming out before it gets tight.

My take down screw SNAPS when I break it loose.

There has to be something different between my SW22 and the problem pistols.