Owner's Manual

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1.
2.
3.
Install the handguard on the MDR by sliding it over the barrel
assembly, Desert Tech logo end first, with the rail at the 12
o’clock position. (Fig. c-1)
Push the captured handguard retention pin through from the
left side to the right side of the MDR receiver until it snaps into
position, flush on each side. (Fig. c-1)
Tighten handguard retention screws with a torque wrench,
using a T25 head, to 30 in/lb. (Fig. c-1)
c) Handguard Installation
To set the gas setting to Adverse, rotate the gas valve within
the gas block until the “A” is centered over the detent and
the gas valve clicks into place. (Fig. b-1)
To set the gas setting to Suppressed, rotate the gas valve
within the gas block until the “S” is centered over the detent
and the gas valve clicks into place. (Fig. b-1)
2.
3.
1.
To set the gas setting to Normal, rotate the gas valve within
the gas block until the “N” is centered over the detent and
clicks into place. (Fig. b-1)
The MDR has three gas settings: “N” (Normal), for regular fire in
generally good conditions and without a suppressor; “A” (Adverse),
for fire in bad conditions (heavy dust, excess humidity, mud, etc.);
and “S” (Suppressed), for fire with a suppressor on the rifle.
b) Gas Adjustment
Fig. c-1
Fig. b-1
CAUTION: The gas block and gas valve may be hot if adjusting during a shooting session. In which case,
it’s recommended you use the tip of a cartridge to rotate the gas valve, if no other tools are readily available.
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