FRAME 13

TM 9-2350-222-20-2-1

SYNCHRONIZATION AND BACKLASH CHECK OF 165 MM GUN WITH

3-4.

GUNNER'S PERISCOPE M32C-RAMP METHOD (CONT)

FRAME 13

Step

Procedure

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

mils.

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

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