Manual
18
the firing of the last cartridge. If this occurs, open the bolt manually and lock
it to the rear. Note: If the bolt will not lock back then push the Carrier Stop
Button rearward and retry locking the bolt rearward. Use your eyes to verify
that the gun is empty.
W A R N I N G
Once you have stopped firing the semi-auto shotgun, immediately push the cross
trigger block safety back to the “on” or “safe” position. Then follow the unloading
instructions above while keeping the muzzle pointed in a safe direction.
GAS SYSTEM ADJUSTMENT: The MP153 shotgun has a unique self-regulating
gas system. It is preset at the factory to function with 12 Ga./2 3/4" (1 1/4 oz.) to
12 Ga./3.5" (steel shot). This system also allows you to fine tune the function of
the shotgun with the gas system nut. By adjusting the gas system nut, you can
make your shotgun function over the complete range of 12 Ga. ammunition and
set the shotgun for optimum function for the user. The gas system nut allows you
to customize the function of the shotgun to your requirements without additional
parts or kits (unlike our competition).
Gas Cylinder Nut: The gas cylinder nut is located under the barrel on the front
end of the gas cylinder. See Figure 31. The gas cylinder nut retains the valve
spring with the valve, which provide the action of the shotgun with light loads as
well as with heavy loads.
NOTE: For the first 100 rounds, use loads 1 1/4 oz. or greater. Your shotgun was
set at the factory to use 12 Ga./3.5" steel shot to 12 Ga./2 3/4" (1 1/4 oz.). If you
wish to use lead shot 12 Ga./3.5" rounds, then you must adjust the gas cylinder
nut two turns counter-clockwise. If you wish to use
loads lower than 12 Ga./2 3/4" (1 1/4 oz.) you must
adjust the gas cylinder nut as required by turning it
clockwise.
Never adjust the gas cylinder nut more than two
complete turns in any direction. For reference use
the notch on front of the gas cylinder. The nut should
be visible through the notch and at most should fit
flush the front end of the gas cylinder. To set the
shotgun back to factory setting, see the mark on the
gas cylinder and adjust as required. See Figure 31.
NOTE: Screw the gas cylinder nut but do not detach
the barrel from the receiver. See Figure 32.
DUCK PLUG PLACEMENT: The wooden or plastic
rod enclosed with your shotgun is a duck plug and
can be placed inside the magazine tube spring from the cap end. The rod prevents
Figure 32
Figure 31