If you have Redfield type windage adjustable bases, you can line up the scope with the barrel. First, cut two V's out of a shoebox so the scope tube can sit in it. Adjust the crosshairs until they don't move when you set it on the box and spin it. This is to make sure the scope is mechanically centered. Then, mount the scope and sight it in, using the windage screws on the base to get the windage roughly right. If you don't have a Windage adjustable base, there's not a lot you can do unless you're using Burris rings with inserts.