Technical data

TM 9-1005-319-23&P 0036
0036-4
INSTALLATION - Continued
M16A4 Rifle and M4/M4A1 Carbine:
NOTE
Organizations that are having difficulty securing the M16A4 rifle with M5 adapter
rail system mounted or M4/M4A1 carbine with M4 adapter rail system mounted are
authorized the following minor alteration to the M12 storage rack.
Due to differing physical dimensions of the M12 storage racks (construction
tolerances), a locking bar is required when storing M16A4 rifles or M4/M4A1
carbines with adapter rail systems installed.
1. Fabricate and install locking bars as follows:
NOTE
The best length of the locking bar for each storage rack varies. The bar should be cut
to the length that gives a very tight fit to ensure the M12 storage rack will meet arms
rack certification criteria when using this locking bar. Measure and cut each length
of angle iron to best fit each storage rack.
a. Cut each piece of stock 1-1/4 in. x 1/8 in. angle iron needed for locking bars (one for each M12
storage rack). The dimensions shown below are approximate. Place the cross locking bars of the
M12 storage rack in the up (unlocked) position.
b. Place each piece of cut angle iron on each M12 storage rack separately to identify the location for
the lock hole. Place the angle iron on the M12 storage rack with the angle iron behind the M12
storage rack lock hole. From the front of the M12 storage rack, trace the M12 lock hole onto the
locking bar. The traced hole on the locking bar is larger than 3/8 in. (0.92 cm).
c. Drill a 3/8 in. (0.92 cm) hole in the locking bar close to the top of the oversized traced hole on the
angle iron. Ensure that as much metal as possible is left in the bottom portion of the angle iron's
lock hole when drilling (1/8 in. (0.32 cm) minimum). Grind all cut and drilled surfaces to remove
burrs.
d. Position the two cross locking bars of the M12 storage rack in the up position.
e. Place the M16A4, M4, or M4A1 weapons with the mounted adapter rail systems in the M12 storage
rack.
f. Place the fabricated M12 locking bar on the M12 storage rack with the lock hole of the locking bar
behind the lock hole of the M12 storage rack. Place a series 200 lock through the lock holes and
lock.