On elevation, one notch equals 5 meters at
200 meters. For windage adjustment, press the
rear sight retainer and move the aperture away
from the barrel to move the trajectory of the
projectile to the left. Move the aperture toward
the barrel to move the trajectory to the right.
On windage adjustment, one notch equals
Figure 3-3.--Quadrant sight assembly.
1.5 meters at 200 meters.
from 50 to 250 meters in 50-meter increments. The
windage adjustment screw moves the blade element
The barrel of the barrel assembly is constructed of
horizontally to provide windage adjustment capabilities.
specially treated and machined aluminum. The barrel
The elevation adjustment machine screw, when
extension is a rectangular, chrome-plated steel bar. It
loosened, allows the blade element to be moved
attaches to the barrel and provides a means of attaching
vertically, providing elevation adjustment capabilities.
the barrel to the receiver assembly. The handgrip is a
molded plastic corrugated sleeve. When the grenade
The M203 also has a quadrant sight assembly (fig.
launcher is being fired, the plastic handgrip allows the
13-3) that connects to the carrying handle of the M16
operator to hold the launcher without discomfort from
rifle. It consists of a sight arm, a range selection
quadrant, an aperture, and post for sighting operation of
the launcher. The range selection quadrant has
embossed range graduations from 50 to 400 in 25-meter
increments. The 25-meter increments also allow for
The receiver assembly consists of an aluminum
better accuracy at a greater number of range variations
receiver that houses the barrel latch, the barrel stop, and
than the quadrant sight (fig. 13-4). For elevation
the firing mechanism. The receiver assembly attaches to
adjustment, turn the front sight post to the right to
the barrel of the rifle, thereby mounting the grenade
decrease elevation and to the left to increase elevation.
launcher to the rifle. The receiver assembly also contains
Figure 3-4.--Installation/removal of quadrant sight assembly.