You should load only one cartridge into the rifle at a
time, and should not load it until you are at the rail, just
before firing, with the rifle pointing outboard in a safe
direction. Never use any cartridge other than one
designated to fire a line-throwing projectile.
Degrees of Elevation
line is approximately 550 feet long and has a tensile
strength of 125 pounds. It is wound around a wooden
spindle in a way that prevents the line from fouling
when the projectile is fired. The line is colored
international orange and is treated with a water-
repellent solution to make it buoyant enough to float on
the surface for at least 24 hours.
NOTE: 0° (degrees) is when the rifle is parallel to the
PREPARATION FOR FIRING
On the M14 rifle, the spindle valve must be in the
If you experience a misfire or hangfire, wait 10
CLOSED (slot parallel to the barrel) position (See
seconds before you eject the grenade cartridge. Report
the malfunction according to OPNAVINST 5102.1.
The maximum reliable range of the line-throwing
projectile is approximately 90 yards when fired from
the M14 rifle. This range depends upon having a dry
This position of the spindle valve is
shot line. You can use a wet line if a dry line is not
described as being in the OFF (horizontal)
available, but it will reduce the range. Table 2-1
position in the first part of this chapter and in
provides the approximate range data for firing from the
Before you fire the line-throwing projectile from
the M14 rifle, elevate and aim the rifle over and across
Maintenance and operation of the Mk 87 Mod 1
the designated target. Although the projectile is made of
line-throwing rifle adapter kit is covered in NAVSEA
rubber, it has enough velocity to cause injury. Keep the
SW350-A1-MMO-010. Kit maintenance is also
rifle elevated until the projectile reaches its target to
covered by a 3-M Systems MRC.
prevent line entanglement.
The Navy currently uses the Browning .50-caliber
machine gun and the 7.62-MM M60 machine gun. We
discuss both of these weapons below.
THE .50-CALIBER BROWNING
Browning machine guns (abbreviated BMGs) are
standard Army weapons used by the Navy. The .50-cal.
BMG now used by the Navy and the Army is the M2.