For what it’s worth. I set our guns in their shooting positions, whether that be bipod or mechanical rest. I took a piece of poster board at 100 yards and while it was on the backer, used a 4 foot level and drew a vertical line from top to bottom on the white poster board. I then looked through the scope while holding the rifle in my shooting position and lined up the vertical crosshair with the vertical line. That’s where I tightened my scopes down. While they were in that position I also leveled to bubbles on the scope. That was the hard thing to get right and may actually still be just a bit off.