TM-9-2350-311-10 M109 Operator's Manual for M109A2, M109A3, M109A4 and M109A5 Download
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TM 9-2350-311-10 3-7 FIRE CONTROL ALINEMENT TESTS AND MEASUREMENTS — CONTINUED 3-7.4 Boresighting the Weapon Boresight using the test target method (para 2–12.2). 3-7.5 Leveling the Cannon Tube a. Leveling the Cannon Tube Using the Cannon Tube Leveling Fixture (if Required) NOTE • Use of cannon tube leveling fixture is required if cannon tube does not have quadrant seats on muzzle brake end of cannon tube. • Recheck gun trunnions. They must be perfectly level for this test. 1 Set zero on the M15 elevation quadrant (1). Elevate or depress the cannon tube (2) until the elevation bubble (3) centers. 3-93