To do so, put the rear sight in the center of the rear sight base. Fire a three-shot group. To adjust the next shot group to the left, loosen the clamping screws and shift the front sight to the right slightly. To shift the group to the right, shift the sight to the left. Tighten the clamping screws of the front sight base and finish zeroing in the normal manner using the windage knob of the rear sight.
Elevation is adjusted by raising or lowering the front sight.
Once the front sight is zeroed, turning the elevation knob sets the range. Shifting the gas block or sight base will normally expose a thin, line of unprotected steel inside the split base. This unprotected surface results from government regulations that render it impractical to phoshphate the barrel before assembly. Paint, oil, or another suitable protectant must protect it. Shooting the rifle as fast as the trigger can be pulled can ruin the barrel in just a few hundred rounds.