New Machine Gun for Joes in Afghanistan / October 09, 2009

U.S. Army infantry units are fighting in the mountains of Afghanistan with a special operations forces machine gun that’s 30 percent lighter than the standard M240B but still packs the killing power of 7.62mm NATO.

Army weapons officials are fielding several hundred MK 48 MOD 1 machine guns in an effort to lighten the heavy loads ground forces, especially machine-gunners, struggle to carry over the country’s unforgiving terrain. The MK 48, made by FN Manufacturing LLC, was first adopted by Navy SEAL teams in 2000. The elite commando units needed a reliable 7.62mm machine gun that was light enough to carry on fast-moving raids and other special missions.

“It’s a great assault gun,” said Army Col. Doug Tamilio, the head of Project Manager Soldier Weapons, the command that overseas Army small arms.

At 18.26 pounds, the MK 48 is about nine pounds lighter than the 27.5-pound M240B. But the 550 MK 48s being fielded are not the beginning of a move to replace the Army’s beloved M240B, also made by FN Manufacturing, Tamilio said. It’s a short-term fix until next year when the Army begins fielding the lighter version of the M240B—the M240L.

The MK 48 fielding is intended to quickly “get something in the hands of soldiers to fight with in the mountains of Afghanistan,” Tamilio said.

The weapon’s appearance resembles the M249 squad automatic weapon, also made by FN Manufacturing. It has the same ergonomic fixed polymer stock and pistol grip. But unlike the 5.56mm M249, the MK 48 is chambered for the potent 7.62mm NATO round and is capable of spitting them out at a cyclic rate of fire of 720 rounds per minute.

The MK 48, while highly reliable, wasn’t designed to offer the long-term durability found in the M240 series machine gun, said Jim Sharp, deputy director for crew-served weapons for FNH USA. The MK 48’s receiver will last about 50,000 rounds compared to the M240’s 100,000-round receiver lifespan.

Tamilio agrees. “It’s a much lighter gun, both in weight and materials,” he said, describing how the MK 48’s bolt will have to be replaced after about 15,000 rounds while the M240s will last for about 100,000 rounds. Despite its durable reputation, the M240 is too heavy to carry long distances, especially up and down steep mountain trails. In some cases, units have chosen to sacrifice firepower to save weight on multi-day foot patrols in Afghanistan’s Korengal Valley, by leaving their M240s at their combat outposts, Army officials maintain.

The MK 48 “breaks away from the traditional support-by-fire position of your heavy or medium machine gun,” said Pedro Gomes, marketing manager for tactical weapons at FNH USA. Before coming to FN, Gomes served as an infantry captain in the Army’s 4th Brigade, 2nd Infantry Division (Stryker Brigade Combat Team). He deployed to Iraq from April 2007 to June 2008. “I didn’t use my 240s dismounted; I kept them always mounted on the vehicle” for highly mobile support fire, he said.

The MK 48 “gives you the option of bringing that higher calibre, more powerful round inside the manoeuvre box,” Gomes said.

Back to the Minimi’s 7.62 Heritage

The MK 48 is very similar to FN’s original Minimi design, which was chambered for 7.62mm when it first appeared in the mid-1970s, Sharp said. When the Army went shopping for a new squad automatic weapon in the 1980s, it chose the Minimi design but in the 5.56mm version, which became the M249 SAW. FN built a streamlined version of the M249, known as the MK 46, for the SEALs in 1998. Two years later, the SEALs asked FN to build them a 7.62mm version of the 46 and the MK 48 MOD O was born. Since then, the MK 48, like the MK 46, has been very popular among Special Operations Command units, such as the 75th Ranger Regiment.

Like most modern machineguns, the MK 48 fires from the open bolt to reduce the risk of rounds cooking off during sustained firing. When the weapon is loaded, the feeding operation begins when the trigger is squeezed. This lowers the sear and starts the bolt moving forward. A roller that sits on top of the bolt assembly travels down the feed lever, forcing it to pivot from left to right. This sets the feed-pawl assembly into action. It pushes the first round on the belt of ammunition into the tray groove.

Dave Hall, a retired Navy SEAL team senior chief petty officer, described the MK 48 as “simple to operate, simple to take apart” and “very, very reliable.”

While deployed in Afghanistan in 2005, Hall’s team primarily used the MK 48 mounted in pairs atop their vehicles. His unit didn’t need to carry its MK 48s in the dismounted role, but he agreed that the weapon is light enough that “if you need to break it off the vehicle and use it somewhere else, you could.”

Hall didn’t find durability to be a problem. “We shot them quite a bit,” he said, adding that firing accurate bursts at 500 to 600 meters was pretty routine. The MK 48’s accuracy at such ranges would come in handy when engaging enemy armed with AK47s and rocket propelled grenades—weapons that greatly lose their effectiveness beyond 300 meters, Hall said. “You are way outside of that—you could just eat their lunch with that thing,” Hall said. “I think the MK 48 is an excellent balance of accuracy and reliability.”