I wanted to touch base and see if anyone has experienced this. My rifle Mcmillian Stock, NF Steel Base, S&B PM2 Rifle Scope. This rifle took a plane flight and rode about 500 miles on rough rocky Alaskan Mtn trails. We would ride to glassing points and spend hours at each point. The rifle rode on the front of the quad mostly inside an eberlestock backpack with the rifle above the pack. Constantly moving around and maybe touching occasionally the front of the quad rack. I know one morning it was hitting pretty good I didn't notice the gun had shifted. When I got home, I checked my zero. It was 1 moa low. What are some thoughts on this?