d. The telescope sighting equipment shall be inserted in the gun tube and the turret shall
be rotated as required to align the borescope reticle with the vertical line of the gun
centerline of the target board.
e. The target shall be positioned with respect to the gun trunnions as follows:
1. When the gun is leveled, in (c), the target horizontal aiming point shall be in line
with the crosshair reticle as viewed through the telescopic sighting system within
1/8 inch. The target shall be raised or lowered to thus position the aiming point.
2. The gun shall be elevated to the 15 degree aiming point and the target rotated, if
necessary, to superimpose the reticle on the 15 degree aiming point. When the
target is thus positioned, so that elevation or depression of the gun results in the
reticle traveling exactly through the zero elevation and 15 degree aiming points,
the target shall be within 0.5 mil clockwise or counterclockwise of a plumb line
3. Laying from low to high borescope reticle shall be superimposed on the zero
elevation aiming point.
f. The ballistic computer superelevation counter shall be positioned at zero by rotating
g. The rangefinder shall be set at 1200 meters, and the left and right side aiming points
superimposed by means of the horizontal and vertical knobs.
h. Aperture stops shall be placed on the gunner's periscope, the rangefinder and the
gunner's telescope, either at the objective or the exit end, as feasible.
i. The gunner's periscope (daylight), the rangefinder and the gunner's telescope reticle
shall be superimposed on their zero aiming points by adjustment of boresight knobs.
j. The borescope reticle shall be superimposed on each of its aiming points laying from
low to high without overtravel. The turret shall be traversed if necessary. Reticles
described in (i) shall fall within their respective tolerance bands at each aiming point.
A reticle line shall be considered within the tolerance bands if half or more of the
reticle line is within the white area.
184.108.40.206.6.1.2 Elevation backlash. To determine conformance to 220.127.116.11.1.2, backlash tests
shall be made in accordance with the following procedure: