I have a Rem. 1100 semiauto with a Hastings rifled barrel. I put on a B square scope mount and a 2.5 power scope. I found if I tightened the mount too much the gun would not cycle properly. If I loosened it too much it was "wiggley" and the gun would not shoot good groups. A gunsmith applied a "bedding epoxy" between the mount and reciever and tightened it just right. Now I shoot 2 3/4 in. groups with Fedreral sabots at 100 yds.

Robin