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 5--60 Change 6 5--6 FUZE SETTING — CONTINUED d. Procedure Number 4, M564 and M565 Fuzes — Continued NOTE • Alining the 20-second mark on lower cap scale with the 0.5-second mark on the vernier scale is an incorrect setting for a 20.5-second fuze setting. Set in this manner, the fuze is actually set to function at 10.5 seconds, causing the fuze to function earlier than desired. • Do not attempt to set the fuze until just before firing. 3 Resetting fuze. If the setting is missed, use the M34 or M18 fuze setter and turn the lower cap in the opposite direction (counterclockwise) 2 or 3 seconds below the desired setting. Then rotate the lower cap in the direction of the arrow (clockwise) and set the fuze on the correct time. Always make the final setting from low to high numbers. 4 Fuzes not fired. If prepared for firing but not fired, reset the fuze, using M34 or M18 fuze setter, by turning the lower cap in the direction of the arrow (clockwise) until the “S” mark on the fuze lower cap scale (6) is in line with the “0” mark on the vernier scale (7). 5 Fuzes fired in heavy precipitation. If M564 fuzes are fired in heavy precipitation (rain, sleet, snow, or hail), occasional downrange premature functioning may occur. The precipitation necessary to cause malfunctioning is comparable to a heavy downpour which occurs during a summer thundershower. The premature rate will vary with the charge fired and the density of the precipitation. 6 7 EXAMPLE OF INCORRECT SETTING OF 20.5 SECONDS