I know these are inexpensive rings but I wonder if anyone else is having problems with them? I am using the 1" medium rings on a Bushnell Banner scope on a single shot shotgun and the same rings on my single shot 243 using another Banner. I have changed the scopes out to a known good scope but still have problems sighting in both of them. they zero in fine at 25 yds, but at longer ranges cannot hold zero. I am thinking that the rings cause the scopes to move in the mount. Just wondering what others have experienced using them? Thanks