Bought two of the .22lr conversion kits to make AR shooting less expensive and at places where 5.56 is too loud, like indoors. Originally had four magazines to go with the kits. Now that I plan to try Steel Challenge with my rimfire converted AR, needed more magazines. There are five runs per stage. Since this is California I was limited to ten round magazines. The conversion kits and magazines have worked flawlessly for some time now. I look forward to the Steel Challenge competition improving my target to target transitions and trigger control with an affordable ammunition alternative, since it requires a minimum 200 rounds.