To reassemble the .50-caliber BMG, replace the major component groups in reverse order. You should follow certain procedures to do the job correctly. These procedures are explained in the following paragraphs.

Replace Buffer Assembly

Slide the buffer assembly into the buffer body group, as shown in figure 13-43, view A. Ensure the spring guide key fits into the slot in the buffer body. Turn the buffer tube until the screwdriver slot is vertical (view B). The arrow on the tube must point to the right. The stud on the tube lock will now engage the serration in the buffer tube. That keeps the tube from turning. Push the buffer assembly all the way forward.

Replace Buffer Body and Barrel Extension Groups

Figure 13-44 shows how these two groups are joined together. Align the breech lock depressors with their guideways in the barrel extension. Also, engage the barrel extension shank to the accelerator claws, as shown.

Push the two groups together. Press down on the accelerator tips to ensure the two groups are locked together. Place them into the rear of the receiver. Push them forward until the buffer body spring lock (fig. 13-43, view A) snaps in place. Properly locked in place, the buffer tube should protrude about 1 1/8 inches from the rear of the buffer body group.

Replace Bolt Group

Figure 13-45 shows how the bolt group is replaced into the receiver. The top of the cocking lever must be

Figure 13-45.-Replacing the bolt group.

forward and the extractor must be down (flat), as shown in view A.

Push the bolt forward, maneuvering it so the front end clears the accelerator tips, as shown in view B. That condition can be seen through the sideplate of the receiver. Continue pushing the bolt forward until the bolt latch engages the notches in the top of the bolt.

Figure 13-46.-Replacing the backplate assembly.

View C of the figure shows an optional procedure. The buffer body, barrel extension, and bolt groups can be assembled outside the receiver. Then, all three groups are inserted as a single unit.