I only tried the .22 unit once and was pleasantly surprised how well it worked. Since the H-Bar at the time had a 1-7 twist which is way faster than the 1-16 the .22LR normally uses, the accuracy really did surprise me. The .22 conversion units work very well in the Vietnam-era M16A1 and Colt commercial SP-1 AR-15s with a 1:12 twist barrel. I put a couple of dozen of our local Civil Air Patrol cadets through a qualification program with them, and the top four were then treated to a session at the Small Arms Firing Course at the national matches at Camp Perry, Ohio, One's gone on to become a USAF sniper and another's qualified expert while at the USAF Academy at Colorado Springs.
Not bad for a bunch of zoomies....
It seems that over stabilizing a bullet works better than under stabilizing them.
My first job was managing Mitchel Hall at Lackland. There wasn’t even a landing strip there. Daddy worked at Eglin for 35 years about as different as two bases can get. He would sometimes fish .45 auto mags out of the trash. I never could tell there was anything wrong with them but several were for a 6 shot .45 auto. Never did know what that was.