SIG 338 Norma Mag going loud: the MG 338 Machine Gun

The MG 338 is chambered in .338 Norma Magnum
January 17, 2020  
Categories: Assorted Ramblings

It’s the first time in more than a hundred years that DoD (and previously the War Department) has safety certified a new weapon system simultaneously with an ammunition type. And to make things even more significant, they certified a suppressor too. We’re talking about the MG 338 Machine Gun from SIG SAUER and the 338  Norma Mag ammunition it throws downrange.

To say the adoption of the new lightweight medium machine gun — and its chosen cartridge — is a big deal is to damn it with faint praise. It’s a huge deal, particularly in the capability that matters most to the people that’ll be carrying it: combat effectiveness.

The search for a .338NM LWMMG first began (or at least was first publicly discussed) back in 2017, when we heard that USSOCOM was working with the USMC to find a weapon system to counter and surpass the Russian PKM…and one that had a suppressed barrel as well. Such a weapon system would be able to reach out nearly as far as the venerable .50 M2 “Ma Deuce” with less weight than the M240 in service and far greater accuracy. Out at extended ranges, the M2 is effectively an area weapon. 338NM can be used to engage point targets at similar distances (though by itself this doesn’t address improved PID).

Polymer cased ammunition would further reduce weight associated with using (and supplying and maintaining) the weapon.

SIG's MG-338 mounted in a vehicle

As redoubtable Eric Graves of Soldier Systems Daily said when he first broke the news back in 2017,

“In my opinion, adoption of this capability is the single greatest small arms capability enhancement to the US military in the last century. It offers the ability to deliver accurate sustained fire at ranges out to 2000m in a package which can be employed by one operator. MARSOC has been following the weapon’s development, but good on the Marine Corps writ large in seeing the value of this proposition. Hopefully, the US Army, a service very concerned about threat overmatch, will move this capability from a Future to Near-Term priority. However, based on recent directed requirement from the 4-Star level, I would not be surprised to see this happen as SOCOM’s program reaches maturity. This will not only enhance the Army’s capabilities but also help control ammunition costs.”

SSD and the .338 Norma Magnum cartfidge

Graves on the range with the SIG .338 Norma Magnum round.


SIG .338 Norma Magnum

The new LWMMG should provide point target accuracy out to ranges that previously could be engaged as area targets only.

Here’s the weapon on the range in early 2019.





When we say MG 338, we ware not talking about the Brazilian highway that runs through Ibertioga. Though we do love a good Brazilian.




Here’s SSD/Graves behind the gun.




The official release from SIG says,

SIG SAUER, Inc. is pleased to announce the United States Special Operation Command (USSOCOM), working closely with SIG SAUER, has completed a safety certification of the new SIG SAUER MG 338 Machine Gun, SIG SAUER 338 Norma Mag Ammunition, and Next Generation Suppressors.  Following this historic official safety certification, SIG SAUER has completed deliveries of multiple systems, comprised of the MG 338 Machine Guns, 338 Norma Mag Ammunition, and Next Generation Suppressors – all researched, designed, engineered, and manufactured by SIG SAUER in the U.S.A.

“The safety certification of the complete SIG SAUER MG 338 system, and delivery of the system to USSOCOM is historically very significant.  For the first time in decades the U.S. Military certified a new machine gun, ammunition, and suppressor at the same time, bringing new innovation, portability, and increased lethality to our ground forces, with all components coming from one company,” began Ron Cohen, President and CEO, SIG SAUER, Inc.  “This certification was achieved following the outstanding performance of the complete MG 338 system through the rigors of the extensive function, durability, and safety tests set forth by USSOCOM.”


The SIG MG 338 bridges the gap between the current machine guns currently in use with the U.S. Military.  In comparison to the current M240 (7.62x51cal) machine gun, which has been in service with the U.S. Military for 60 years, the SIG MG 338, is noticeably lighter, weighing only 20 pounds, and provides significantly more range and lethality.  In comparison to the M2 (.50cal), which has been in service with the U.S. Military for 110 years, the MG 338 is approximately one-quarter the weight, and in a historic first, offers a man-portable solution with similar effective-range.  Making this system even more desirable are the new SIG SAUER Next Generation Suppressors which drastically reduces the impact of harmful toxic fumes and signature, making the operator less vulnerable.  

The SIG SAUER MG 338 machine gun is a belt-fed, lightweight medium machine gun weighing under 20lbs., chambered in 338 Norma Mag.  The MG 338 features a short-stroke gas piston system and a proprietary recoil mitigation system, with a free-floating, quick-change barrel, ambidextrous controls, switchable feed tray, charging handle that can be alternated to either side depending on operator preference, and as a modern, multi-caliber, modular system the new SIG MG 338 is easily convertible to 7.62x51cal.

“We are incredibly proud of this historical accomplishment and honored to have received this safety certification by USSOCOM for the performance of the complete MG 338 system,” concluded Cohen.

Upon official news of the certification, Graves said,

“I recently had an opportunity to fire the SIG SAUER MG 338 machine gun. It is extremely controllable and weighs less than an M240.”





Note: the “Lightweight Medium Machine Gun” project is not connected to “Next Generation Squad Weapon” program.

You can read more at the Marine Corps Times or on The Drive.

For some further (and more detailed) history on the MG 338’s development, check out SSD’s article from Range Day 2019.




Palmetto State Armory Clearance


From the original SOURCES SOUGHT notice:

LWMMG specifics: The LWMMG should fire the belted .338NM round of ammunition with a polymer case. The LWMMG should weigh less than 24 pounds unloaded with a barrel length of 24in. The LWMMG should have a rate of fire of between 500-600 rounds per minute. Weapon shall be compatible with current rail mounted aiming systems with the ability to incorporate more advanced fire control technology. The system should include both a suppressed barrel and an unsuppressed barrel that can be rapidly changed. The LWMMG should include a tripod that is lightweight and provides the stability and accuracy required to engage targets at extreme ranges. The LWMMG should be able to mount in current machinegun mounts designed for the M240B/C. The weapon should have sufficient accuracy to engage area targets and vehicles at 2,000m.


See also the General Dynamics LWMMG.




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