Got a Leupold VX-1 2x7 on an Encore 209x.45, had it there for two seasons, never had any problems. Had a cheap 2.5x7 on a T/C Blackdiamond for two seasons before that and didn't have any problems either. I think a lot goes into proper mounting, I mean having a quality base and rings and mounting them to the rifle properly. Everything needs to be good and tight without crushing the scope tube. Using threadlock on the screws helps too. I have to agree with the guy about warranties and their importance. If you buy a quality scope, they will back it up.