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 603 of 775
TM 9--2350--311--10
Change 6
5--67
5--8
LOADING AND FIRING — CONTINUED
•
Do not fire the M549/M549A1, M864, and M825/M825A1 projectiles if obturating band is
missing or broken. Separation of the projectile and rocket motor may occur causing injury
to personnel. If the obturating band is displaced and can be repositioned and remain in the
groove, the projectile can be fired.
•
Do not assemble M3 series green bag charges with M4 series white bag charges. Critical
malfunction could result causing injury to personnel.
•
Do not load or fire M231 charges with M232/M232A1 charges. Critical malfunction could
result. Do not load or fire more than two M231 charges or less than three M232/M232A1
charges.
•
Firing a round with an obstruction in the cannon tube can cause inbore premature
detonation causing death or injury to personnel.
•
Do not fire an M864 projectile if the outer weather seal is damaged (torn, punctured, or
peeling) to the extent that moisture can enter the base burner assembly. A loss in range
(short round) may result and short rounds fall on friendly forces. Return projectile to
ammunition supply point (ASP).
•
For M864 projectiles marked with three solid white circles 120
°
apart located on the ogive
(above the weight zone markings) observe the following warnings to prevent injury to
personnel.
Do not fire the M864 projectile if it has been dropped or if it shows evidence of denting,
flattening, or gouging to the lifting plug, grommet, rotating band, or boatail area.
If during handling and/or loading, the M864 projectile base separates, call EOD personnel.
Do not fire the M864 projectile if the obturating band is missing or broken because it may result in a
short round. If the obturating band is displaced and can be repositioned and remain in the groove,
the M864 projectile can be fired.
Do not fire the M864 projectile if it has been delivered without the grommet.
1
Make sure round is clean and fuze is present and fully seated.
2
Make sure there are no obstructions in the cannon tube.
3
Check cannon firing mechanism to see that primer expended in previous firing has been removed.
4
Remove grommet from projectile.
WARNING
•
Never load a propelling charge into the chamber by increments. Only the fully assembled
charges will be used. Critical malfunction could result causing injury to personnel.
•
Dirt or grease left on the projectile rotating band could cause failure of the projectile to seat
properly in the forcing cone on ramming. Firing an unseated projectile could cause inbore
explosion resulting in injury or death to personnel.
NOTE
If firing the M549/M549A1 projectile, remove the rocket motor-off cap from the base of the
projectile by turning in the direction of the arrow (clockwise). The M549/M549A1 projectile is
authorized for rocket-on firings only.
5
Load fuzed projectile into cannon and ram it solidly through the firing chamber into the forcing cone so it
will not fall back on the propelling charge. Round must remain wedged into the forcing cone at all angles
of elevation.
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