The procedure

Serious zeroing is a short sequence executed well. First comes pre-alignment: on bolt actions, with the bolt removed, you sight through the bore at a reference in the distance and bring the reticle onto that same point (bore sighting), or you use a collimator; the only goal is to be on paper with the first shot. Then, at 100 meters, from a solid rest and in good conditions, you fire a three- to five-shot group aiming at the center, without correcting between shots; you measure the offset of the group center from the point of aim, vertically and horizontally; you convert it into clicks (at 100 meters a tenth of a MIL is one centimeter: it is the geometry of Chapter 26 at work); you dial the correction and fire the confirming group. The point of method, which Chapter 33 will prove with statistics, has to be said right here: you correct on the group center, never on the single shot, because the single shot is noise and the center is signal. Figure 29.1 walks through the three steps, with the group center marked in each.