when adjusting it 1 click moved it in the proper direction 1/4" at 100 yards. Always. Now I move it and it impacts far more then what I moved it and when moving it back will go to a different point of impact.
Seeing how you know the scope and the rifle . You have checked to make sure the mounts are tight . Not to mention your years of experience . I think you got it right . Sounds like there is something up with the scope . Did you try the old tapping on the knobs to reset the reticle . I've always loved that theory . I'll lightly tap the scope cus the recoil of the 30-06 is not enough