Thanks for the replies. The scope is fine on anothe gun, 30-06. The mount is the fixed cantilever mount on the barrel (the screws are tight). My only option is to try new rings I suppose. Otherwise, I'll be looking for an 870 with the receiver drilled and tapped for a scope and remove the cantilever mount. I know if if I can't get it ironed out, this gun doesn't see the deer woods shooting like it is.