Wow that is areal hard head. I have one of the arbor bore sighters and it does put me on paper. I personally start at 25 or 50 yards becuase it is easier to see bullet impact and know I am on paper. After I get it zeroed at 50, then I move to 100 yards and tweak it. It works for me and now, as in most cases when I zero, I go to the range with 5 rounds, well more, but use 5 rounds or less, to verify the zero. Then I move to the next rifle and verify, etc, etc. During the season I may go once a week for 3-5 rounds just to make sure it is where it was suppose to be.........

but three boxes, definate hard head!