is the scope new or is it one from another rifle? could be the scope has paralax which you will find out if you set the rifle on a solid base and without touching the rifle look through the scope and slowly move your head from top to bottom and left to right. if the crosshairs seem to move with your eyes then its time to get a new scope. ive had a couple scopes do this and had to replace the scopes. remember that when buying a new scope you get what you pay for. dont be cheap. some scopes might not be able to handle the recoil of a rifle if its a magnum caliber.