Marine Corps Systems Command is equipping Marines with the
updated M2A1 .50-caliber machine gun, increasing Marines’
survivability and lethality on the battlefield.
serves as an upgrade to the legacy M2 machine gun currently used by
Marines across the Corps. The updated M2A1 is easier and safer to
use due to three major changes: a quick-change barrel, fixed
headspace and timing, and a flash hider that reduces the weapon’s
signature by 95 percent at night.
September 20, 2016 - Marines with Company A, Infantry Training
Battalion, School of Infantry-West (SOI-West), fire the M2A1 .50
caliber heavy machine gun as part of their basic infantry training
at Marine Corps Base Camp Pendleton, Calif. The M2A1 is new to the
Marine Corps and has set headspace and timing which is an upgrade
from the older M1A1 which requires manual adjustments. SOI-West
trains riflemen, infantrymen and assault amphibian crewman in MOS
skills across the infantry training continuum. (U.S. Marine Corps photo by Lance Cpl. Joseph Prado)
“M2s are the most reliable heavy machine gun,” said Maj.
Harry Thompson, team lead for General Purpose Weapons at
MCSC. “The improved M2A1 makes Marines more lethal because
they’re able to get rounds down range quicker. Marines will
have better mobility because of the fixed headspace and
timing—it’s much quicker to move the gun from position to
position and put it back into action. Because they’re less
exposed, Marines will have better survivability too.”
The current M2 requires Marines to manually set
headspace and timing before firing, after assembly, and
after required barrel changes when the barrel becomes
extremely hot from high volumes of fire. “Headspace” is the
distance between the face of the bolt and the base of the
cartridge case when it is fully seated in the chamber.
“Timing” is the adjustment of the gun so that firing takes
place when the recoiling parts are in the correct position
Correct adjustments of both are
necessary for the gun to work properly and continue to work;
improper adjustments can lead to malfunctions that could
potentially injure the user or damage the weapon. Fixed
headspace and timing reduces operator risk and eliminates
the need for Marines to master and execute this
The fixed headspace and
timing on the M2A1 enables the machine gun’s second major
improvement—the quick-change barrel, said Thompson.
“Marines no longer have to manually screw the barrel in to
set the headspace,” he said. “Instead, the barrel pops into
the receiver and locks in place quickly, similar to the
M240B machine gun.”
Having a quick-change barrel
improves Marines’ readiness by reducing the amount of time
they are exposed to enemy fire and shortens the amount of
time the weapon is out of operation. By spending less time
manually adjusting headspace and timing settings, and having
the ability to change the M2A1’s barrel quickly, Marines can
respond faster and more efficiently to enemy fire.
The third major improvement is the flash hider at the end of
the barrel, said Thompson. By significantly reducing muzzle
flash, Marines can better mask their position in firefights.
The flash hider also limits white-out conditions caused by
the brilliance of the weapon firing, enabling Marines to use
night vision devices more effectively.
“All in all,
MCSC will be fielding around 3,600 M2A1s to Marines,” said
Kelly Sullivan, a program analyst for General Purpose
Weapons at MCSC. “We completed Phase I fielding in March
2017, which covered infantry units, the majority of
infantry-like units and infantry Reserves. We’re currently
starting Phase II, which should run through the end of May.
The fielding process will be will be finished during FY18.”
The M2A1 is one of the many capabilities acquired and
managed by MCSC’s Infantry Weapons Systems.
By U.S. Marine Corps Ashley Calingo
The U.S. Marines
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