Check Out the Marine Corps’ Fearsome-Looking Upgraded Shotguns

U.S. Marines Corps is fielding improved shotguns in a variety of units. Combined with an accessory kit, Marines are able to pick a weapon that best suits the mission at hand.

The so-called “Military Enhancement Kit” (MEK) for the 12-gauge Mossberg 500A2 includes a new barrel with a fearsome-looking muzzle device, fixed and collapsible buttstocks, and a replacement pump with attachment points for accessories on three sides. The Marines have had standard Mossberg 500-series shotguns in service since at least the 1980s.

The upgraded components offer an advantage in “multiple tactic scenarios,” Marine Corps Gunnery Sgt. Michael Flor explained in a video presentation on the system. He noted that Marines fast-roping from a helicopter or an Osprey could get the longer, basic M500A2 tangled in the rope or caught on the aircraft itself, potentially causing a serious accident.

Before the MEK, the Corps only issued the Mossberg in one standard configuration, with a basic 18.5-inch barrel and no easy way to strap on flashlights, lasers, vertical forward grips or other accessories. The new version has a similar overall length, but actually has a 16″ barrel with a special vented muzzle device specifically to help with blasting open locks and hinges on doors.

In addition, Marines can choose to fit a compact, sliding buttstock similar to the one on the M4 carbine to trim additional inches off the gun, or dispense with a stock altogether and go with a pistol grip. Armorers can still install an improved, fixed stock when appropriate.

The MEK appears to have made its debut in the U.S. military in April 2009, when U.S. Army’s 10th Special Forces Group bought the gear for operations in Afghanistan and Iraq. Four months later, the U.S. Army Special Operations Command announced plans to buy more kits from a company called Pro Patria, Inc. in North Carolina. At that time, it cost the Army nearly $625 to buy the MEK’s two separate packages. The 2009 deal was worth more than $680,000 in total.

“This is a critical mission requirement as the current barrel assemblies on the issued Mossberg shotgun system are inadequate and presents a safety problem,” the Army explained in its justification to sole-source the contract directly to Pro Patria without a formal competition. When blasting down a door, the vented barrel would help chuck debris away from the shooter, help relieve pressure from the gasses trapped inside, and reduce recoil.


But while the MEK will certainly make the Mossbergs safer and handier, don’t expect to see Marines necessarily using them any more often than they are now. The weapons have proven themselves useful in very select situations, such as close-range security details or breaking down doors. The new upgrades are almost entirely focused on improving the gun’s handling in the latter situation.

Of course, with American troops carrying shotguns into battle since World War I, the services have tried repeatedly to make the firearms more broadly useful in combat. Weapons designer and U.S. Army officer Carroll Childers famously spent decades trying to refine one such weapon while working at the Naval Surface Warfare Center in Dahlgren, Virginia.

His initial concept, dubbed the Special Operations Weapon, would be a fully-automatic multipurpose tool for elite and regular troops fighting in built-up areas, against guerrillas on the jungle or while guarding outposts during a conventional war. Three name changes later, Pentagon had expanded the requirements to include a suite of new ammunition that would include regular pellets, explosive grenades, illuminating flares and more.

An unmodified Mossberg 500.

An unmodified Mossberg 500.


All of this eventually morphed into the futuristic-looking Close Assault Weapon Systems (CAWS) project. By then, Childers no longer had any involvement in the program and was disgusted by how U.S. military officials had twisted and upended his original ideas.

“My concept was never about to develop a gun for the sake of ‘re-inventing the shotgun,'” he wrote to Benjamin Schemmer in 1982. Schemmer, then-editor of Armed Forces Journal, had just written a piece about the latest incarnation of the program.

“Although, this will be the end result if the politicians, strap hangers, meddlers, and hand-wringers continue to get involved,” Childers continued in his tersely worded letter, which Small Arms Review posted in its online archive. “Nobody said a ‘shotgun’ was magic.”

A Marine breaches a

A Marine breaches a “door” with a regular Mossberg 500 during a training exercise.


In the end, the Pentagon balked at the complex CAWS and bought hundreds of a special version of the Benelli M4 called the M1014 as the new standard for all the services instead. This 12-gauge weapon was similar to stereotypical pump-action shotgun, but had the ability to fire in a pump-free semi-automatic mode. It also featured a collapsible stock.

“I think the M1014 is the best shotgun the Marine Corps has right now,” Gunnery Sgt. Trocon Bestman, an anti-terrorism force protection Marine, told the service’s reporters in 2015. “We used others in Iraq and the M1014 was the most accurate I’ve used for breaching in comparison to those shotguns.”

Beneli M1014 in a Marine’s hands., USMC

However, the Mossbergs, along with similarly old off-the-shelf 12-gauge Remington 870 types, continued to serve Marines around the world. There is a similar commercial accessory kit available for the 870s, called the Modular Combat Shotgun.

If these upgrades are any indication, regular pump-action shotguns still have a lot of service life left, albeit in limited roles.

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Joseph Trevithick Avatar

Joseph Trevithick

Deputy Editor

Joseph has been a member of The War Zone team since early 2017. Prior to that, he was an Associate Editor at War Is Boring, and his byline has appeared in other publications, including Small Arms Review, Small Arms Defense Journal, Reuters, We Are the Mighty, and Task & Purpose.