I have a 10 GA single barrel that I have an Aimpoint 9000SC red dot on. A week before the season this year I decided to remove the 1 pound steel rod in the stock to make it lighter. The rod was a very tight fit and did not want to come out. I ended up beating the devil out of the stock to get it out, and knew that I was going to have to re zero it after that much abuse. However, took it to the range and it had not moved a bit. I think movement has more to do with how secure the base and rings are than the internal adjustment of the scope.