I made a quick setup that you can use without a target. This is just for setting up your reticle so it's aligned with the bore.
1. Level the rifle at the leveling point.
2. Look down the bore from the muzzle and center the bore on the plumb line.
3. Aim a flashlight into the Objective.
4. Without moving the rifle, rotate the scope until the vertical cross hair is aligned with the plumb bob. If the projection is left or right of the projection then adjust the windage adjustment on the scope to bring it over the top of the plumb line and do any fine adjustments to scope.
5. Carefully and evenly tighten the scope rings to 15 inch lbs.
6. Take it to the range and finish sighting it in.
When you're finished your reticle will be perfectly in line with your bore. This doesn't do anything for elevation, you'll need to take it to the range for that.