U.S. Special Operators Will Soon Be Using This 6.5mm “Assault” Machine Gun

The gun offers better range and accuracy over smaller belt-fed squad automatic weapons.

byJoseph Trevithick|
Assault Rifles photo


FN America has unveiled a prototype of its new Mk 48 Mod 2 machine gun in the 6.5mm Creedmoor cartridge, which it developed in response to a U.S. Special Operations Command requirement. American special operations forces are interested in acquiring an “assault” machine gun in this caliber, which would offer better range than existing weapons that use the smaller 5.56x45mm cartridge, but would still be lighter than more traditional light machine guns.

The American subsidiary of Belgian gunmaker FN Herstal revealed the Mk 48 Mod 2 for the first time at the National Defense Industry Association’s annual Special Operations Forces Industry Conference (SOFIC), which began on May 20, 2019. The machine gun is also available chambered for the 7.62x51mm cartridge, just like the previous Mod 0 and Mod 1 variants.

FN debuted the 7.62x51mm Mod 2 version last year, which includes a number of other upgrades over the earlier models, including an improved buttstock with an adjustable cheek rest, a new handguard and bipod assembly, revised charging handle, and a number of internal refinements. “Once development is complete, existing Mk 48 Mod 1 models can be configured at the armorer level to the Mod 2 variant or newest [6.5mm Creedmoor] caliber with the addition of the upgrade kit and barrel conversion,” according to an official press release.

U.S. Special Operations Command (SOCOM), through the U.S. Navy’s Naval Surface Warfare Center Crane Division in Crane Indiana, also known simply as NSWC Crane, has been looking into a 6.5mm machine gun since at least 2016. At that time, a number of different specific cartridges were under consideration, including 6.5mm Creedmoor, .260 Remington, and .264 USA, the latter being a round that the U.S. Army developed internally for its Army Marksmanship Unit (AMU).

A US Army soldier fires an existing 7.62x51mm Mk 48 Mod 1 machine gun., US Army

The ostensible goal of the smaller assault machine gun program is to give special operators an improved means of hitting targets that are out of range of 5.56x45mm weapons, such as the M249 Squad Automatic Weapon (SAW) and its special operations specific variants, but without the weight and bulk of a 7.62x51mm light machine gun. NSWC Crane is also leading the development of a larger .338 caliber machine gun, which would fill a similar intermediate role, but between 7.62x51mm weapons and the venerable .50 caliber M2 “Ma Deuce.”

There had also been talk in the past about the possibility of a belt-fed weapon optimized for very close range using a specialized cartridge, such as the .300 Blackout cartridge, a round you can read about in more detail here. At the time of writing, NSWC Crane had not yet responded to our queries for information about the status of that development.

A 2016 NSWC Cranebriefing slide mentioning a short-range belt-fed weapon potentially chambered in .300 Blackout., USN

Choosing the Mk 48 series as a starting place for the 6.5mm assault machine gun makes good sense. The original Mk 48 Mod 0, which special operations forces first began using in 2003, was already supposed to offer a lighter weight 7.62x51mm weapon to fill the same general operational need.

Regular U.S. military units also subsequently began using the Mk 48s, which are around 10 pounds lighter than the U.S. Army’s standard M240B infantry light machine gun. That service even developed a backpack-mounted ammunition system for the weapon, akin to ones seen in Hollywood action flicks, such as Predator, for dismounted patrols, which also made its way into special operations use.

A US Navy SEAL carries a Mk 48 Mod 1 with a "Predator-style" backpack-mounted ammunition system., DOD

Unfortunately, the original guns were so light that they would suffer a loss of accuracy during sustained firing due to the severe recoil. There were also overheating and reliability problems, all of which prompted the development of the improved Mk 48 Mod 1 variant. It is probable that the smaller 6.5mm cartridge may further help mitigate any remaining issues.

The 6.5mm Creedmoor cartridge also actually offers better range than the larger 7.62x51mm. As a result, SOCOM is separately in the process of developing a designated marksman rifle using this round, which will give operators improved capabilities over existing weapons of that type without having to employ a true sniper rifle.

A briefing slide describing the benefits that a 6.5mm Creedmoor or .260 Remington designated marksman rifle would offer over existing 7.62x51mm guns., SOCOM via Soldier Systems Daily

Having a new designated marksman rifle and an assault machine gun that use the same cartridge could be very valuable, especially for special operators during long-duration missions or in emergency situations where they might need to share ammunition in a pinch. There could be interest in a 6.5mm Creedmoor battle rifle in the future, or a conversion kit for the existing 7.62x51mm Mk 17 Special Operations Forces Combat Assault Rifle-Heavy (SCAR-H), but there are no such plans at present.

Since FN’s gun is simply another variant in the Mk 48 line, SOCOM will have the option of simply rechambering its inventory of those guns to fire the 6.5mm round, rather than buying new weapons. This could also help ease logistical strains depending on how much of the 6.5mm version has in common with other Mod 2s or earlier variants.

Using the Mk 48 as a starting place will also ease training requirements, since the gun has many of the same basic controls and features as earlier versions. All of this will help make the Mk 48 Mod 2 a particularly cost-effective development.

As of 2018, SOCOM expected the development of the weapon to wrap up some time this year. The goal is for special operators to begin receiving their new 6.5mm assault machine guns by the end of 2019.

Contact the author: jtrevithickpr@gmail.com