Don't hesitate to buy either the drums or stick mags. A good friend of mine was involved in the development and debugging. I have several prototypes. They are reliable and much better than alternatives which came before, especially those from another well known manufacturer of .22 conversion kits.
FYI: From the beginning, the intent was to be sure the Black Dog mags would run on fast firing full autos, such as the Thompson with a .22 conversion kit. Depending on which one you have and how you set it up, rate of fire may be from 600 to nearly 1200 rounds per minute. The drums and sticks keep up. I like them.
So you should have few, if any, problems with a simple .22 semiauto rifle, if it is in tune and well maintained.