Had this on my AR-15. Was AWESOME for close quarters. At 25 yards, hit groupings quarter size. I really enjoyed this site and want one for my S&W M&P 15-22.
http://swfa.com/Mueller-Quick-Shot-Archery-Scopes-C139.aspx
http://swfa.com/Mueller-Quick-Shot-Archery-Scopes-C139.aspx