In what could represent a revolutionary departure in traditional western machine gun design philosophies, General Dynamics Armament and Technical Products (GDATP) has unveiled a prototype for a new Lightweight Medium Machine Gun (LWMMG) that provides range lethality close to that of a traditional .50-caliber heavy machine gun at the weight of a traditional 7.62 mm medium machine gun.
Although some early firing demonstrations have been conducted with select elements in the special operations community, the weapon was publicly unveiled at last week’s Joint Armaments Conference, Exhibition and Firing Demonstration in Seattle, Wash. (May 14-17, 2012). The annual event is sponsored by the National Defense Industrial Association (NDIA).
The 24-pound weapon design features a fully collapsible stock, providing superior mobility and portability in mounted and dismounted operations. Perhaps most significantly, weapon developers utilized the .338 Norma Magnum cartridge, which provides significantly increased accuracy and lethality out to distances of 1700 meters.
According to Kevin Sims, senior manager of business development and capture at GDATP, “about two years ago” the company “recognized a potential capability gap that our U.S. forces were having in theater. That capability gap was between 7.62 and .50 caliber, and it involved the ability to engage targets before you are being engaged yourself. In many cases the U.S. forces had the low ground and enemy forces had the high ground. And if you’re receiving PKM fire you may be in a position where you can’t really respond. So bounding into position to react to that contact was very difficult.”
Noting that the M2 .50-caliber weapons are not available in every engagement scenario and that the weapon’s weight usually precludes use on dismounted patrols, Sims explained, “The M240, while it’s a great weapon system, is sort of drifting at 800 meters, especially if you’re shooting ‘up.’”
“On the flipside, at a closer range, you have ‘energy issues,’” he said. “My example would be an adobe mud hut at 600 meters. If there’s an enemy target inside of that structure and you don’t have a [Carl] Gustav, and a 240 is your only heavy weapon, it has to be a precision game. If you are just shooting at the wall you may not be penetrating it. So, having a better penetrating capability to defeat targets at closer ranges is also important.”
Drawing on a company legacy from Saco Defense, manufacturer of the M60 7.62 mm machine gun, and its role as original equipment manufacturer for the M2, the company began looking for options to fill that capability gap.
“The PSR [USSOCOM Precision Sniper Rifle] was still rumbling around, and it showed us that there’s a need for extended range capabilities,” he noted. “And we designated that at about 1500 meters. So we started looking at what would give us that range and accuracy. Of course some of us are prior shooters, so we said, ‘The .338 caliber’ [approximately 8.38 mm]. Then it became a question of, ‘If we design a .338 caliber machine gun, how much does it have to weigh?’ Because you have recoil forces that you have to mitigate.”
He added, “Usually mitigating those recoil forces involves either adding mass to the weapon system or length to the receiver. But we have a technology called ‘Impulse Averaging’ that was used on the XM806 [lightweight .50-caliber machine gun program]. But that technology alone didn’t get us there on a suppressive fire capability.”
However, by combining the lessons learned with other technologies like a short-stroke gas piston, the company came up with a Short Recoil Impulse Averaging technology that substantially reduces recoil and improves target retention.
The reduced recoil and target retention features were clearly evident during live fire opportunities provided to several attendees at the NDIA gathering.
In an effort to enhance producibility and reduce system cost, the LWMMG design also relies on available subsystem components rather than exotic material developments.
Sims said that the design focused on the .338 Norma Magnum cartridge over the more commonly-known .338 Lapua for several reasons, including increased barrel life.
The Norma cartridges, joined by a company-developed link design, currently feature a 300 grain Sierra Match King projectile. However, Sims was quick to highlight the availability of other potential projectiles based on user requirements.
“The output of all that is that we have a 24-pound machine gun, which is 3 ½ pounds less than an M240 Bravo today, firing 500 shots per minute,” Sims summarized. “There are no exotic materials inside of it. It has the recoil of a 7.62. There’s no recoil mechanism that comes back into the stock; we could use a spade grip or a folding stock; it [recoil] all happens in the receiver. At this design stage we have elected to go with a 6-power scope to give us a broad view, and an E-4 machine gunner can get behind this weapon and actively engage, with point precision, targets at 1000 – 1200 meters. Your machine gunner can do that now.”
Significantly, the design features are “scalable” and could be applied to future weapon requirements for calibers ranging anywhere from 5.56 mm to .50 caliber.
Sims said that the development of the prototypes, which were funded as an internal research and development investment by GDATP, took approximately 12 months.
The next 12 months will feature a number of prototype demonstrations for potential customers.
“We’ve got quite a bit lined up,” he said. “It’s going to be a pretty busy year for us with this weapon system.”