Owner's Manual

12 13

Gripping the charging handle (right or left side), press down

and pull to the rear of the charging channel, then lock it to the

rear by lifting the charging handle upwards into the locking

cutout and releasing it. The charging handle should remain in

the locking cutout. (Fig. a-3)

Ensure the barrel lock screw is in the “Unlocked” position, and

the two barrel retention screws are loose. (Fig. a-4)

Ensure the bolt head matches the chambering of the barrel.

(Fig. a-5)

Insert the barrel assembly into the MDR receiver, barrel extension

end first with the gas block rail at the 12 o’clock position. When

properly seated in the receiver, there should be around a 1/16”

(1.5mm) gap between the front edge of the upper receiver and

the back edge of the gas block. (Fig. a-6)

10.

Release the bolt assembly by pressing the charging handle

downward to disengage it from the locked-back position.

Rotate the rifle to the left side. Using the 5mm hex wrench

side of the multi-tool, rotate the barrel lock screw to the

“Locked” position. (Fig. a-7)

Tighten and torque the two 5mm barrel retention screws to

80 in/lb. (Fig. a-7)

Fig. a-3

Fig. a-6

Fig. a-7

Fig. a-4

Fig. a-5

SETUP