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 2–12 PREPARATION FOR FIRING — CONTINUED 2–1 2.5 Loading the 155MM Cannon — Continued b. Power Ramming — Continued 10 11 12 To prevent injury to personnel, stand clear of breechblock. Do not close breechblock unless red igniter pad is visible. Cannoneer no. 1 commands “CLOSE” and lifts operating cam (7). After breechblock (2) is closed, cannoneer no. 1 ensures that witness marks (18 and 19) are alined. If witness marks are not alined, do the following. (a) Release operating handle (3) and push in clutch pin (20). (b) Hold clutch pin (20) in and push forward on operating handle (3). this should rotate breechblock (2) closed. • if breechlock does not lock, do not load primer to prevent injury to personnel. Report unsafe condition to supervising officer and unit maintenance, then unload cannon assembly (para 2–14). • NEVER insert primer in primer chamber unless breechblock assembly is closed and locked. Ignition of propelling charge with breechblock not fully closed presents a critical hazard to crew. • Don’t force primer into primer chamber, Forcing primer could prematurely charge causing the howitzer to recoil resulting in serious injury to the crew. NOTE Use only M82 primer in cannon assembly (para 5-2.4). ignite powder Cannoneer no. 1 inserts primer (21) into primer chamber, If primer will not go in, primer chamber is probably dirty. Clean primer chamber and vent hole by inserting reamer assembly into chamber as far as it will go and rotating briskly. After primer is inserted, cannoneer no. 1 announces, “PRIMED.” 2-210