Figure 3-23.--Rear sight aperture.
Figure 3-25.--Front sight, M16A1.
The rear sight consists of two apertures, as shown
in figure 3-23, and a windage drum with a spring-loaded
detent, as shown in figure 3-24. The aperture marked
"L" is for use for ranges beyond 300 yards; and the
unmarked aperture is for use for ranges from 0 to 300
yards. Adjustments for windage are made by pressing in
on the spring-loaded stud with either a pointed
instrument or the tip of a cartridge and rotating the
windage drum in the desired direction.
The front sight of the Ml6A1 rifle consists of a
rotating sight post with a spring-loaded stud (fig. 3-25).
Adjustments are made by using a pointed instrument or
a tip of a cartridge. To raise or lower the front sight post,
depress the spring-loaded stud and rotate the post in the
Figure 3-24.--Windage drum.
desired direction of change. A spring-loaded detent
keeps the post from being moved accidentally. To raise
the strike of the bullet, depress the detent and rotate the
button (fig. 3-6). Pull the charging handle to the rear (fig.
sight post clockwise.
3-7), ejecting any round from the chamber. Inspect the
chamber and receiver to ensure that it is clear. Releasing
Each click of elevation or windage adjustment will
the charging handle will allow the bolt to close. To keep
move the strike of the bullet a specific distance at a
the bolt open, depress the lower portion of the bolt catch
specific range. At a range of 100 yards, one click of
before returning the charging handle forward (fig. 3-8).
either elevation or windage on the sights of the rifle will
The rifle is clear only when no case or round is in the
move the strike of the bullet approximately 1 inch, or
chamber, the magazine is out, the bolt carrier is to the
2.54 centimeters, up or down.
rear, and the selector lever is on the SAFE position.
SIGHTS OF THE RIFLE
The 5.56-mm ammunition, as shown in figure 3-26,
The sights of the rifle are adjustable for both
for the M16 rifle is classified as small arms ammunition
windage and elevation. Windage adjustments are made
and is issued in the form of a complete round. A
on the rear sight; elevation adjustments are made on the
complete round (cartridge) consists of all the
components necessary to fire the weapon once; that is,