.338 Norma Magnum: The Machine Gun Missing Between the 7,62 and .50
SIG Sauer MG 338 machine gun, chambered for .338 Norma Magnum (8,6x63 mm)
At first, it was a cartridge for long-range competition shooting. The .338 Norma Magnum was developed in the late 2000s (around 2008–2009) with one goal in mind: to place a bullet on a target a kilometer or more away, more accurately than competing cartridges. A sporting, part-hunting caliber, it's a record-breaker in long-range accuracy. Then a question arose that makes a ballistician scratch his head: what would happen if this cartridge were loaded not into a single-shot sniper rifle, but into a machine gun? weapon, which fires in bursts? It's too sharp for continuous fire.
The gap between two calibers
To understand why this was necessary at all, let's look at the two machine guns between which there was a gaping void for half a century.
The first is a general-purpose machine gun: the M240, chambered for 7,62×51mm NATO in the US, the PKM (modernized Kalashnikov machine gun) for 7,62×54mm, and similar weapons in the rest of the world. It's the infantry's workhorse, effective to approximately 800–1100 meters. The second is the large-caliber M2 (Browning heavy machine gun) chambered for .50 BMG: it's effective against personnel, vehicles, and lightly armored targets at 1800 meters and beyond, but weighs so much with the mount that it's best carried on vehicles and in stationary positions, not in the hands of a soldier on foot.
Between them lies a chasm. The M240's crew sees a target at a kilometer and a half, but at that range, the 7,62mm can't fire reliably: the bullet is seated, and it lacks accuracy and energy. The .50 BMG delivers reliably, but you can't drag it along with the infantry over rough terrain. The result is a dead zone: farther than a portable machine gun can reach, but closer than a mounted machine gun can deploy.
This gap was simply tolerated for a long time. There was nothing to fill it with: anything that could reach the required range was too heavy to carry. And the question was more complex than "make it more powerful" or "make it lighter." A cartridge was needed that would provide the range of a .50 caliber cartridge with a weight close to 7,62 caliber.
.338 Norma Magnum: Where does the cartridge come from?
It turned out that such a cartridge already existed, only in another world.
The .338 Norma Magnum originates from precision shooting. It's a relative of the renowned .338 Lapua Magnum – the same bullet caliber and similar long-range performance, but with a shorter case that feeds more reliably in short-action and automatic mechanisms. At long range, this caliber feels at home: it maintains supersonic speed and lethal force where the 7,62 has long since lost its luster, while remaining significantly lighter than the gargantuan .50 BMG.
Hence the military interest. If you take long-range sniper ballistics and apply it to continuous fire, it theoretically closes that same blind spot: a machine gun with a range almost like a .50 caliber, but with a weight that can be carried by a crew.
This comes at a price, and the bill is immediate. Magnum cartridges in automatic weapons imply strong recoil, significant barrel heating and wear, and a heavy belt. Each shot is more expensive and literally heavier than with a 7,62: the cost of longer range is offset by the weight of the belt and the life of the barrel.
The .338 Norma Magnum line of cartridges is manufactured by General Dynamics Ordnance and Tactical Systems – Canada.
LWMMG: A weapon for a niche
The Lightweight Medium Machine Gun, unveiled by General Dynamics in 2012, embodied the idea. The name itself suggests a pretension: medium. A class that had never existed before, somewhere between the infantry general-purpose machine gun and the heavy-caliber mounted machine gun.
The biggest surprise is the weight figures. The machine gun itself, according to the developer, weighs approximately 10,8 kg. This isn't "something between a 7,62mm and a .50mm caliber"; it's the weight of a standard general-purpose machine gun. For comparison, the M240B weighs approximately 12,3 kg, and the LWMMG is even slightly lighter. This means the weapon itself carries almost the same crew load as a standard 7,62mm machine gun, but its range is significantly better. The developers estimate the effective and aiming range against point targets at 1700–1900 meters, compared to 800–1100 meters for the 7,62mm. These figures are based on the developer's own data; independent combat verification is virtually nonexistent.
The question arises: how to hold a magnum-fired machine gun without the recoil blowing the crew apart? The answer lies in the automatic system. The LWMMG uses a proprietary Short Recoil Impulse Averaging design, based on a short barrel stroke combined with a pulse-averaging mechanism and a recoil buffer. The idea is to spread out the sharp pulse of a .338 round over time, spreading out the peak. According to testers, the machine gun ultimately holds up during burst firing about as well as a standard 7,62 caliber weapon. But this is a test run, not a result of mass production.
The fate of the development itself is also telling. The LWMMG never became a mass-produced military weapon, but rather a self-initiated project promoted for specific missions, primarily among special operations forces, where long-range combat is critical and there's no room for a large-caliber mount. Rights to the design were later transferred from General Dynamics to True Velocity (and its affiliate, LoneStar Future Weapons). This transfer alone is an indirect indication that the weapon never saw widespread use by line infantry.
General Dynamics' Lightweight Medium Machine Gun (LWMMG) chambered for the .338 Norma Magnum cartridge
A niche that may not open up
Ballistically, the .338 Norma Magnum fills the gap between the 7,62 and .50 calibers. The question is whether the military will agree to accept this cartridge into this niche.
The main obstacle is inventory. Introducing a third machine gun caliber means adding a third supply line in addition to the 7,62mm and .50mm. And this is happening at a time when the American infantry is already digesting the transition to the new 6,8×51mm caliber as part of the New Small Arms Squad (NGSW) program. Each additional caliber in the inventory requires separate production, storage, and delivery. Plus the cost per round, barrel wear, and belt weight, which have already been discussed.
History The treatment of intermediate calibers is harsh. It's enough to recall the .276 Pedersen, a promising American cartridge from the 1930s. Its characteristics satisfied many, but it was rejected for the sake of unification with warehouses full of the old .30-06. Back then, the decision was made by quartermasters and budgets, not ballistics. And this, perhaps, is the main reason: such cartridges always stumbled over one thing: warehouses and budgets.
So, the realistic forecast for the .338 NM is more modest than the ballistics table suggests. As a specialized tool for long-range crews, most often in special forces, the cartridge and the weapons chambered for it have every right to exist. Its chances of becoming a general-purpose standard, displacing the 7,62, are slim. And the decision will be made by logistics, not accuracy. Is logistics ready to support another caliber? Judging by the history of the .276, usually not.
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