When I mount a scope on a rifle, I am sure by all means it is plumb, and level, as this left hander can make it. Shooting it in bears this out. BUT when a right hander picks up my rifle to shoot he says ' hey your scope is crooked' . I am sure this is some kind of optical anomaly but it puzzels the heck out of me why this diff occurs between mounting for a lefty and mounting for a righty. If I mount the scope as if I was right handed, then it appears crooked when I switch the gun to my left shoulder. Any suggestions from you physics students out there???