SYNCHRONIZATION AND BACKLASH CHECK OF 165 MM GUN WITH
GUNNER'S PERISCOPE M32C-RAMP METHOD (CONT)
While looking through daylight eyepiece of gunner's periscope, adjust boresight knobs (1)
and (2) to align aiming cross of reticle on same aiming point as gun (view A).
Write down settings of boresight knobs (1) and (2).
Have driver return tank to level ground.
While looking through breech boresight hole (3) with binoculars (4), slowly lower gun
(without over travel) until cross formed by threads (5) on gun muzzle is lined up with
target aiming point (TM-10).
Repeat steps 3 and 4 in frame 11 to check backlash of gun and sight for gun positioning
from high to low.
Subtract boresight knob readings gotten when positioning gun from low to high from
those gotten when positioning from high to low. The difference is the backlash error.
Repeat frame 12 and steps 1 through 6 above for gun elevation angles of 178 and 267
Check boresight readings taken at the different gun positions. If backlash error computed
in step 6 exceeds 0.3 mil for periscope at any gun position, notify support personnel. If
readings are within tolerance, go to frame 14.
GO TO FRAME 14
Para 3-4 Cont