looks like i'm a little late but i've had a PA micro dot for about a year now. originally mounted on my MP15-22, held up nice and easy to zero. i just got the MP15 Sport and mounted the PA micro, 1-2 clicks and it was bullseye at 30 yds. it held its zero thru 100 rnds, single shot, double, triple tap and a mag dump. wow factor... i left it on Sunday afternoon when i 'checked' on her and did some reload practice. Checked on her again today, Tuesday and the micro was still on and bright as ever. I can't afford the high end dots nor the high end rifles. it works for what i need, and i would recommend it.