The internal dimensions of the 15-22 receiver are mil-spec but the sidewalls are thicker. This leaves the ends of standard trigger pins slightly recessed but since they are secured internally, no problem. CMC offers longer anti walk pins for 15-22’s.
I’m trying to decide whether to stick with the OEM pins or use the anti-walk pins that came with my new Rise Blitz trigger. I initially installed the Rise pins but it isn’t clear to me when to stop tightening the screws. They seem flush with the side of the lower receiver but they didn’t seem like they were getting very snug. They aren’t loose but neither snug and I am hesitant to keep tightening them as I heard you could deform the polymer. Was considering going back to the oem pins just to eliminate any question but not sure if/when anti-walk pins are needed with a new trigger…?