Getting the right scope rings makes all of the difference in the world.  I was talking to a shooter today who had experienced some problems with fatigue while shooting his .308.  It came down to the height of his scope rings.  An instructor pointed out that they were too high for him.  A switch to lower rings and he was good to go.

Your scope should feel comfortable to look through when you mount the gun.  If you have to raise your head up or lower it too much, you are not in the proper shooting position.  You should be able to mount the gun with a good cheek weld and see clearly through the scope.

Get the right rings and watch your shooting improve.