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 575 of 775
TM 9--2350--311--10
Change 6
5--43
Section II.
PREPARATION FOR FIRING
5--3
GENERAL
WARNING
To prevent projectile malfunction and possible bodily injury, ensure that projectile upper
temperature limit stays below 125
°
F(52
°
C). Shade projectiles when weather is expected to be
hot, i.e., the outside temperature is expected to exceed 100
°
F(38
°
C) during the day.
a. Temperature Limits
Unless otherwise specified, observe the following limits when firing.
1
Lower limit is --40
°
F(-
-40
°
C).
2
Upper limit is 125
°
F(52
°
C).
b. Temperature Check Procedures for Modular Artillery Charge System (MACS), M231 and M232/M232A1
NOTE
Temperature will be taken using the standard issue M1A1 powder thermometer. The operating
temperature of MACS is --50
_
F through +120
_
F.
1
Lift the edge of the red seal on either end of the increment and peal the seal back.
WARNING
Do not jab the round end igniter bag with thermometer or any other object that may be used to
break through the edge of the red seal. Black powder is impact sensitive and forceful impact of
the bag may cause an accidental ignition.
NOTE
Do not puncture the combustible case since this makes the increment defective.
2
Lift the edge of the igniter bag and insert the powder thermometer under the cloth igniter bag and down
along the inside of the center core.
3
The thermometer must stay in the increment until the temperature stabilizes.
c. Packing and Unpacking Ammunition Components
Retain packing materials for repackaging, as required.
WARNING
The M82 primer is the only authorized primer to be used in the M109A2/M109A3/M109A4
M185 and M109A5 M284 cannon assemblies. Do not use the MK2A4 primer in these cannon
tubes. The propellant may not ignite.
1
The M3 series propelling charges are packed two per metal container, with or without the MK2A4
primer. The M4A1, M4A2, M119A1, M119A2, M203, and M203A1 propelling charges are packed one
per metal container.
2
The M231 is packed with four increments (two per extraction sleeve) in each metal container and the
M232/M232A1 is packed five per metal container. Increments in extraction sleeves that are not full will
be combined to reduce the number of partially loaded containers. These increments will be repacked
into their correct type of extraction sleeve and the repacked sleeves returned to their correct container
(correct type and lot number) using the following procedure:
(a) Place one of the end cushions into the end of the extraction sleeve and lock in place using the
velcro strap.
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