C9, TM 9-2350-230-12
and body) are not interchangeable between XM44 and
(2) Checksight.
The checksight is an opto-
mechanical device for checking the alignment of
XM44E Series. Except where specifically indicated
otherwise, operation and maintenance procedures are
the tracker and telescope with respect to each
identical for all models.
other, and to check the proper functioning of the
Periscope (fig. 2-26) is a major component of the fire
missile tracker. The checksight is mounted in a
control system and serves as the primary "night" fire-
cavity on the left side of the M149 Mount.
control instrument. The Periscope consists of two major
(3) Tracker. The tracker is the eye of the missile
subsystem and monitors the missile in flight with
assemblies, the head assembly and the body assembly.
the line of sight.
The head assembly provides a large entrance aperture
and the means for elevating and depressing the field of
c. XM44 Series Gunner's Periscope.
view. The body assembly houses a large aperture
optical system to pass as much of the available light as
possible, an image intensifier tube, an optical system to
NOTE. The XM44 Periscope, together with the later
view the tube screen, a reticle projector system to
design XMi44E1 and XM44E2, comprise the "XM44
superimpose a ballistic reticle pattern on the target
Series". In this manual, models are differentiated as
image, and the unity power optical system for direct "day"
follows: "XM44 Series" all "'XM44E Series" all except
viewing.
XM44 "XM44" XM44 only.
d. Individual Weapons Night Vision Sight. The
These periscopes are all interchangeable as complete
Individual Weapons Night Vision Sight (fig. 2-29) is a
units, but major assemblies (i. e. head
battery-powered, electro-optical device for visual
observation and aimed fire at night under ambient sky
light for the cal. .50 machine gun, M2, HB and also can
be used as a hand-held surveillance device. The sight
offers maximum freedom from the possibility of enemy
detection.
TABLE 2-9. OPERATION OF M119 OR M127 TELESCOPE, XM44 SERIES PERISCOPE,
AND ARMAMENT BORESIGHT PROCEDURE
STEP
PROCEDURE
FIG/ITEM
ALIGNING GUN-LAUNCHER AND 7.62MM MACHINE GUN
1
Position vehicle on level ground.
2
Secure muzzle boresight (black thread) in reference marks on gun 2-23/A
muzzle with strap or tape.
3
Open breech and insert breech boresight assembly.
4
Position right telescope of binocular M17Al over hole of breech
boresight assembly and select a distant aiming point at approxi-
mately 1200 meters with sharply defined vertical and horizontal
lines. Align muzzle boresight cross hairs on aiming point by
traversing and elevating weapon.
5
Align machine gun.
OPERATING GUNNER'S M119 OR M127 TELESCOPE
6
Turn vehicle MASTER SWITCH on.
7
Turn FIRE CONTROL selector to CONV position. The correspond-
ing lamp above the selector will illuminate.
8
Turn RETICLE LIGHT rheostat knob on reticle dimmer box clock-
2-25/1 &
wise for increased intensity of reticle lamp.
9
Adjust headrest to fit gunner.
10
Pull and turn diopter knob until proper focus is obtained.
2-52/2
2-36
