Mechanically Zeroing the M4/M4A1 and the M4 MWS
Mechanically zeroing the weapon is only necessary when the weapon zero is questionable, the weapon is newly assigned to the unit, or the weapon sights have been serviced. If necessary, the soldier should mechanically zero the weapon as follows:
- Adjust the front sight post (1) up or down until the base of the front sight post is flush with the front sight post housing (2).
- Adjust the elevation knob (3) counterclockwise, when viewed from above, until the rear sight assembly (4) rests flush with the detachable carrying handle and the 6/3 marking is aligned with the index line (5) on the left side of the carrying handle.
- Position the apertures (6) so the unmarked aperture is up and the 0-200 meter aperture is down. Rotate the windage knob (7) to align the index mark (8) on the 0-200 meter aperture with the long center index line on the rear sight assembly.