Figure 14-21.--Misfire procedure: Dislodging the round.
Figure 14-20.--Range indication.
rounds lodging in the barrel because of burrs, excess
paint, oversize rounds, or foreign matter in the tube.
A HANGFIRE is a round that gets lodged in the
barrel for one reason or another, and the round does not
The range indicator (fig. 14-20) consists of a vial
strike the firing pin. Thus a hangfire cannot be
that contains a ball that moves when the cannon is
distinguished immediately from a misfire. Any round
elevated or depressed to indicate the firing range.
that fails to fire should be treated as a misfire. When a
The black scale is for charge one; the red scale is for
firing malfunction occurs, any member of the squad
charge zero. The yellow index (range 3 on the red scale
noticing that a misfire has occurred immediately
and range 10 on the black scale) is a warning reminder
announces MISFIRE. When conditions permit, the
to brace the baseplate before firing.
mortar crew should wait approximately 1 minute before
attempting to clear the misfire. This waiting period may
The ammunition handler prepares the cartridge. As
avoid an accident, caused by a delayed action of the
the gunner sets the firing selector in the T (trigger)
ignition cartridge. If the barrel is excessively hot, it
position, the assistant gunner inserts the round into the
should be cooled to avoid cooking off the misfire. Wet
muzzle, releases the round, and assumes a safe position.
sandbags or water or both maybe used to cool the mortar
The gunner lays-in the weapon by using the range
barrel. All persons not actively engaged in clearing the
indicator and sighting over or on the side of the muzzle
misfire should be kept at a safe distance until the misfire
for the azimuth. Holding the mortar steady, the gunner
has been removed.
assumes a safe firing position. When the weapon is on
target, the gunner squeezes the trigger to fire, then
The above procedures are similar for both the
releases the trigger in preparation for the next round.
conventional mode and the hand-held mode. The major
difference is the support needed for the M225 cannon,
since the hand-held mode is without a biped. Sandbags,
MISFIRES
empty ammo boxes, or anything else that will furnish
the required support may be used to maintain safe
A MISFIRE is a round that has been inserted in the
elevation of the muzzle.
mortar but has failed to fire. A misfire is a complete
If a misfire occurs, the gunner sets the fire selector
failure to fire. It may be caused by a faulty firing
to the T (trigger) position and squeezes the trigger twice
mechanism or a faulty element in the propelling charge
to confirm the malfunction. If the weapon fails to fire
explosive train. A misfire in itself is not dangerous, but
after the second try, any crew member noticing it
since it cannot be immediately distinguished from a
delay in functioning of the firing mechanism or from a
announces MISFIRE. The gunner changes the firing
hangfire, it must be handled with care. Mechanical
selector to the S (safe) position, and then kicks the lower
malfunctions may be caused by a faulty firing pin,
portion of the cannon (fig. 14-21). This is to dislodge
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