It is the quality control of these guns that is the problem, not Richard's quality control. The specs of these guns are all over the place. Like Z-mags the .22lr magazines need to fit all the guns. So if the mag catch pin hole was drilled 0.005" or 0.010" too high in your gun, you feel that is Richard's responsibility to make a product for that? Think about the tolerance of the two rounds. If the bolt catches a 9mm round 0.005" high, as long as the mag doesn't rub the bolt, it will feed. On the other hand 0.005" when talking about .22lr, is quite a bit. Think about how much tolerance 9mm could take compared to .22lr. It is so much easier to take a little material away than to add a little bit. So I would imagine that Richard kept things on the high side so if the magazines didn't fit, it is a simple matter of a few strokes of a file on the mag catch instead of adding 0.005" to the mag catch. It is tough to design anything for Mac style guns. And .22lr is even harder because of the tighter tolerances. My hat is off to Richard for making a .22lr kit at all. The mag catch is a $15 part. If you don't want to modify your catch then modify your mags. At least it is too high. It would be much more problematic if the magazines were too low. YMMV.
Scott