Owner's Manual

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Fig. h-1

Open the upper receiver by pressing the rear and center

takedown pins to the outward most position and tilt the upper

receiver up from the lower receiver, if it’s not already open.

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, and torque the barrel retention screws to 80 in / lb.

(Fig. h-2)

h) Conversion Kit Installation

Insert the barrel assembly into the MDR receiver, barrel exten-

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

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

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

the back edge of the gas block rail tower. (Fig. h-1)

Fig. h-2

CONVERSION & REASSEMBLY

Using a small flat tool, tap the back of the magazine

conversion bar until it slides off. (Fig. f-2)

Fig. f-2

Fig. f-3

Press the .223/.300 BLK magazine conversion bar onto the

magazine release main bar and rotate the magazine catch

back into place. (Fig. f-3)

Push the rear and middle takedown pins to their furthest

outward position.

Lift the back of the upper receiver to expose the magazine

conversion latch.

Push the magazine release while pushing the magazine

conversion latch in and down. The magazine spacer should

slide out the bottom of the magazine well. (Fig. g-1)

g) Magazine Spacer Removal (.223 and .300 BLK)

Fig. g-1