Accuracy testing of rifle loads or establishing a precise zero requires a “precision” target. However, it’s possible to encounter an inch or more of aiming error when attempting to repeatedly position the intersecting crosshairs of a duplex reticle in the center of a round bull’s-eye. A better solution is to make a target that doesn’t allow aiming errors.
Use a ruler and a 1/4-inch-tip black Sharpie to draw intersecting 6-inch-long horizontal and vertical lines on a sheet of 8 ½x11-inch white copy paper. Add a small mark above the crosshairs where you want your group to zero. Tape this sheet to your target backing and, back at the bench, match the crosshairs in your scope’s reticle to the crosshairs on the target. The contrast between black lines and white paper makes it easy to confirm your hold. If you see one set of crosshairs through the scope, your point of aim won’t vary more than 1/8 inch per shot. If you see two sets of crosshairs, you’re off the mark.