General Dymanics’ Lightweight Medium Machine Gun, .338 Norma Magnum

Matthew Cox reports on the GD Lightweight Medium Machine Gun

OK, so we all know the Pentagon has no money. But if it did, General Dymanics’ Lightweight Medium Machine Gun, chambered in .338 Norma Magnum might be worth a look.

GD’s Ordnance and Tactical Systems division was showing off the 23-pound LWMMG at Modern Day Marine 2013, touting it as the needed bridge between the M240 and the M2 .50 caliber machine guns.

“We wanted a round that could provide capabilities to eliminate the gap between 7.62mm and .50 cal,” a GD official said. “We needed a round that could provide accurate, effective fire on target beyond 1,500 meters.”

The LWMMG fires a 300 grain .338 caliber bullet and is capable of effective fire out to 1,700 meters, compared to the M240 round which is effective out to 1,100 meters.

The time to introduce this gun was early or mid-way through Operation Enduring Freedom. For better or worse, the military is not going to adopt a new machine gun cartridge in the immediate future.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Gunhead

    “For better or worse, the military is not going to adopt a new machine gun cartridge in the immediate future.”
    I dunno, they seem pretty keen on the LSAT…

    • Cornelius Carroll

      I’d really like to see the LSAT make it into production. It’s time we moved to ceaseless ammunition IMO

      • LCON

        Caseless and case less telescopic are still problem childs for production better to go polymer cased. You can keep the existing weapons systems with out any changes. Its all in the casing

    • Ian

      It will flounder.

    • vitor roma

      Well, the LSAT is mainly be tested in 5.56mm. Of course it would be nice if they adopt it in 6.5-7mm.

  • scw

    LSAT is development project and there is no reason to believe the army will actually it.

  • Geoff a well-known Skeptic

    How does the round compare to 9.3 Swedish? 6.5X55, 9.3X57 and 9.3X62, the bigger round was for Machine guns around the early 20th Century and they chambered machine gunners rifles for the same round. Geoff Who wonders how many qualification rounds they fired back then.

    • swede1986

      9.3×57 and 9.3×62 have never been used in Swedish machineguns. You’re thinking of the 8x63mm Bofors round which we used in Browning machineguns.

    • Kirill

      .338 Norma is comparable to .338 Lapua in a sense. Its got slightly more power and has a slightly better trajectory.
      So in short it out preforms all of those, even though, as far as I know, 9.3×57/62 have never been used in Swed. MGs

    • Eurocopter

      The 6,5×55 is a fantastic and very flat shooting round that has been used in scandinavian and german bolt action rifles for more than a hundred years. But it has never been used in an MG.

      • swede1986

        The 6.5 has been used in several different MGs.

  • Matrix_3692

    Just asking out of curiosity, why not just call in an artillery barrage or an air strike at that range?

    • Artillery takes time to call in and splash down, planes don’t fly in all weather. Area-of-effect small arms definitely have a role for modern and motorized infantry.

      • Hunter57dor

        this, plus, sometiems, they are in an area where it wouldn’t be advisable, for example, if the enemy has significant AA built up, or its a no fly zone for political reasons, or they just happen to not have the resources right that minute to service your request.

    • Clint Notestine

      plus a few 300 grain rds vs a couple 2000 lb bombs

    • Andrey Martim

      Also is more expensive.

    • fasteddiez

      Because you will need the OK of a pursed lip mil lawyer, or some higher level commander who’s in locked and cocked CYA mode……. who don’t care too much about the condition of the condition you’re in.

  • Tom – UK

    At least with all the experience from Afghan/Iraq and a couple other conflicts when it comes to the next big scrap there will be plenty of off the shelf fit for purpose technology. We all seemed to get caught with our pants down when we went to these initial conflicts and now there’s plenty of developments.

  • dp

    This thing actually should replace both calibers on top and the bottom. Anti-personnel plus anti-material in one; rationalisation of logistics in most visible form.

    • Hunter57dor

      for light armor, sure, but you can’t beat a .50 for everything else that needs some extra punching.

  • dansquad

    Maybe I,m oldfashioned, but I think it´s time to consider indirect fire from mgs a worthy option, as it was in WWI. Anyway, what´s the point of this if you can use mortars or “Ma Deuces”? This Upper-medium/Lower-Heavy MG is IMHO just hype or simply another must for “tacticool” minds.

    • allannon

      Portability. Ma Duece is fine when you have a couple guys or a humvee to carry her luggage. But there are times when you need something more portable, but with more authority than 7.62.

      • dansquad

        If portability means that you don´t use a tripod or another stable mount using this gun, think about dispersion spraying .338 bullets beyond 1,500 mts… Result: it would be fired at usual m240 distances. Maybe I´m mistaken but, although it seems a formidable gun, I don´t see any major improvement for the battlefield with that gadget. I stand still thinking that vs static foes at long range, you use a Barret (accurate & portable enough), and mortars or grenade-launchers (portable artillery) if they are moving. And simply m240 indirect fire to put them on the run. But perhaps it´s an oldfashioned way of thinking…

        • allannon

          An M249 has a bipod already, but lacks the ballistic characteristics to reach as far as .338 Norma. If stability is required beyond the bipod, a buttstock monopod would be a simple and lightweight addition that could be folded out of the way when needed.

          A Barrett, while a fine weapon, can’t act as a SAW, where this could.

          It’s a hybrid weapon for when something beyond a SAW is required or desireable, but an M2 or M82 are impractical (for instance due, respectively, to weight or lack of dispersion fire capability).

          I’d hazard that even if adopted, current SAWs would remain in deployment because they’re still very useful. But there are situations where a machine gun with heavier and longer-range rounds would be nice, and that’s the role this would be intended to fill.

  • Cornelius Carroll

    Go big or go home

    • Anonymoose

      Rebarrel it for .510 Whisper!

  • iksnilol

    Why didn’t they make it in .338 Lapua? Since some of their sniper rifles also use .338 Lapua. No need to add another cartridge.

    • Hunter57dor

      my guess, (i have not been informed) was probably the high cost of the .338 lapua round.

      • Raven

        That, and .338 Norma is slightly optimized over Lapua. The Norma has a max pressure that’s slightly higher, and it will accept a 300-grain MatchKing with less difficulty.

      • Anonymoose

        >implying .338 Norma is cheaper than .338 Lapua

    • Rogier Velting

      A bit late, but from what I read that was because of the case taper of the Norma making more suitable for belt fed weapons.

  • Lance

    Only down side is no one sues .338 cal round in the military so its a wildcat caliber for military use. If it was .300 Win mag like the XM-2010 it get more looks.

    • Anonymoose

      .338 has a much flatter trajectory than .300 Win Mag, though. Also, a lot of NATO countries are now fielding .338 Lapua sniper rifles, while the main user of .300 Win Mag sniper rifles is the US Army and Navy, and Sweden is pushing their improved version of the .338 Lapua.

      • bbob

        .338 Lapua is not .338 Norma. A .338 has no flatter trajectory than a .300 Win Mag as they are two different things, one is a bullet, the other a cartridge.

        • Anonymoose

          Both .338 Lapua and .338 Norma (the improved version of the Lapua) have flatter trajectories than .300 Win Mag. A .338 Lapua/Norma MG has a better chance of being adopted than a .300 Win Mag one because a lot more countries’ militaries are already using the Lapua and Lapua instead of the Win Mag, and they have more range and more potential against both people and light-armored targets (the Norma especially so, which makes it an even better choice in a machinegun).

  • LCON

    This looks like a great mg but it was built for OEF, and with our current leadership set to leave. The need is not there. Best case maybe a Allie will buy it. And the Afghanis have the pk series that sits about in the same class. Perhaps when the time comes later in the decade the army or Marines will take a look at trying to reduce the weight of the m249 a scaled down version with PCP rounds will pop up to compete against LSAT as is maybe socom will take a look.

  • Agitator

    Sustained fire from a .338NM sounds like it could be quite the barrel-burner.

  • Esh325

    I’ve never heard the US military or any military express that the current .30 caliber and .50 caliber machine gun system is grossly inadequate. If it were, I think they would have figured it out 100 years ago. I think it’s just marketing.

  • Nicholas Mew

    Here is my answer.

    • CaptainSlaughterboard

      Why the fuck Russians use such big centipede with machine gun?
      I would rather use spiders!

    • noob

      my shoulder bleeds just looking at that.

    • Secundius

      @ Nicholas Mews.

      I think of one better, the Boys, Kynoch & RG .55-caliber/14.3mm (.5625-actual)
      Anti-Tank Rifle w/36-inch barrel.

  • metalfosho

    Pretty soon they’ll need a round to bridge the gap between the .338 and the .50. And a round to bridge the gap from .338 and .308.

  • trooper

    How about replacing the 5.56×45 and the 7.62×51 with a 6.5mm GPC (ie the 6.5 Grendel)? Then upgrade the M240 to the .300NM?