Figure 14-2.--M225 cannon.
ASSEMBLIES AND COMPONENTS
Figure 14-3.---Bipod assembly (M170).
The barrel assembly used with the 60-mm mortar is
the M225 cannon (fig. 14-2). It consists of a barrel, fire
selector, firing pin, trigger, and range indicator. The
lower portion of the barrel is externally threaded. The
external threads provide extra cooling surface and also
help to strengthened the barrel. The baseplug ends in a
spherical projection that is flattened on two sides. The
spherical projection fits into the locking cap of the M7
and M8 baseplates. The M224 has two firing modes:
conventional and hand-held. Each mode requires
different equipment and procedures.
Figure 14-4.--Baseplate (M7 and M8).
The BIPOD ASSEMBLY (fig. 14-3) consists of
principle of this weapon is similar to the 81-mm mortar
three major assemblies: the leg assembly, the elevating
or any other mortar.
mechanism assembly, and the traversing mechanism
The BASEPLATE ASSEMBLY (fig. 14-4) is of
one-piece construction and it supports and aligns the
mortar for firing. The baseplate contains a rotating
The M225 cannon and M8 baseplate weigh
socket that holds the spherical projection of the barrel.
approximately 18 pounds. This is a lightweight and
The socket retaining ring holds the rotating socket in
highly mobile weapon that can be used in this mode on
place. The open end of the socket MUST ALWAYS
point in the direction of fire. The bottom of the baseplate
The SIGHT UNIT (M64/M64Al) (fig. 14-5) is the
has reinforced ribs that hold the baseplate in position
standard sight used with the 60-mm mortar. Once a sight
after being seated in the ground.
has been calibrated on a mortar, it should always be used
In the conventional mode, the M7 baseplate, the
with that mortar. It is used for laying-in the mortar for
sight unit (M64/M64Al), and the biped are used. The
elevation and deflection. The sight unit consists of a