TM-9-2350-311-10
HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A2, M109A3, M109A4 AND M109A5
TECHNICAL MANUAL; OPERATOR’S MANUAL
NOVEMBER 1994
TM-9-2350-311-10 - Page 584 of 775
TM 9-2350-311-10
5-52
5-6
FUZE SETTING — CONTINUED
a.
Procedure Number 1, MK399, M557, M572, or M739 Series Fuzes
NOTE
Point–detonating (PD) fuzes, with superquick (SQ) or delay functioning are shipped for SQ
action. The MK399 fuze is shipped set on the DLY (DELAY) mark.
1
If superquick action is desired, check the setting to make sure it is set at SQ.
2
To set fuzes for delay action, use screwdriver end of the M18 fuze–setter wrench (1) or similar tool and
turn slot (2) 1/4 turn to aline with index mark indicating DELAY (or DLY on MK399 fuze).
b.
Procedure Number 2, M501 Series Fuze
WARNING
Exercise extreme care when handling an M501 series fuzed projectile to prevent injury to
personnel. Manhandling or dropping could cause the M501 series fuze to function, expelling
the base plate, and contents. When handling a projectile assembled with the M501 series
fuze, exercise extreme care to protect the M501 series fuze from impact. Keep pull wire on
M501 series fuze in place until immediately prior to firing.
CAUTION
To avoid malfunction, do not use M501 series fuzes with cocked or loose lower caps. Mark
such M501 series fuzes “defective” and return to ammunition supply point.
NOTE
The M501 series fuzes are shipped with the index mark on the lower cap alined with the S
engraved on the base.
1
Time setting.
(a)
Check fuzes for cocked or loose lower caps.
(b)
To remove safety wire before setting, pull end of safety wire from hole in lower cap, sliding safety
wire off end of M501 series fuze.
(c)
With M27 fuze setter (3), set M501 series fuze by rotating lower cap to desired time in
counterclockwise direction or in the direction of the arrow marked on lower cap. The M501 series
fuze is properly set when the index mark on the lower cap is alined with desired time, in seconds,
engraved on the base.
(d)
If the round is not fired after the M501 series fuze is set, reset the M501 series fuze to safe (S)
position and place the safety wire in its proper position.
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