Candidate's Name______________Rank________Unit_________________

TASK 1: SET HEADSPACE AND TIMING ON A M2 CALIBER .50 HEAVY MACHINE GUN

1. Set headspace.

a. Raised the cover.
b. Retracted the recoiling parts and screwed the barrel all the way in.
c. Backed the barrel off two notches.
d. Cocked the weapon and allowed the bolt to go forward.
e. Set headspace with retracting handle pulled back until the barrel extension was 1/16 of an inch from the trunnion block.
f. Inserted the "GO" end of the headspace gauge into the T-slot.
g. The "NO GO" end of the headspace gauge could not enter the T-slot.

2. Set timing.

a. Ensured that gun was cocked and bolt was forward.
b. Retracted the recoiling parts and placed the FIRE timing gauge between the barrel extension and the trunnion block.
c. Removed the backplate.
d. Screwed the timing adjustment nut down until it touched the trigger lever.
e. Pressed up on trigger lever and made one-click adjustments until weapon fired.
f. Turned timing adjustment nut up two more clicks.
g. Locked backplate in position.
h. Re-cocked machine gun and let bolt go forward.
i. Checked timing using NO FIRE.

NOTE: Adjusting screw should be set at the same place for each candidate.

3. Completed performance measures in sequence.

NOTE: Scorer must physically check the candidate's work to ensure that proper headspace and timing have been met.

CHECK: PASS______ FAIL______

REASON(S) FOR FAILURE

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SCORER'S SIGNATURE________________DATE________________

Is this a retest? YES______NO______

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