2 SIG Sauer Belt-Fed NGSW Rifles and a New Light Warfighter Option

There are average days at the range and then there are incredible days at the range. One such incredible day occurred recently as I walked out in the warm May sunshine in New Hampshire. The purpose of my journey up north was to visit the good folks at Sig Sauer and get some time on their new belt-fed machine guns. As I said, it was an incredible day on the range, running the new lineup of SIG belt-fed NGSW rifles. While we would ultimately get time on a variety of weapons during the stay, my focus and deep interest was on the new go-fast shooters.

SIG Sauer Belt-Fed NGSW Rifles and Possible M4 Replacement

The genesis of Sig Sauer’s development of belt-fed machine guns is based on the military’s NGSW or Next Generation Squad Weapon program.

The Army states, “The Next Generation Squad Weapons (NGSW) Program is a future prototyping effort, using middle tier acquisition authority, to develop and create operationally relevant, squad-level lethality in order to combat increasing threats. The program is informed by soldiers’ feedback.”

That boils down to they are looking to replace current weapons with better weapons. The core of this program is to find a replacement for the M249SAW and the M4 carbine with new weapons chambered in 6.8×51. The intent is to significantly increase lethality and probability of hit at the squad level.

Due to the nature of the general-purpose ammunition, the 6.8mm projectile will outperform even the most modern 5.56mm and 7.62mm ammunition. These weapon systems will give soldiers significant capability improvements in accuracy, range, signature management and lethality.

The LMG-6.8

First up was the SIG LMG-6.8. This is an air-cooled machine gun that fires from an open bolt. The LMG-6.8 has ambidextrous AR-style ergonomics, quick-detach magazines, increased M1913 rail space and a quick-detach SIG-developed suppressor. The feed tray is a side-opening design that not only makes it easier to manipulate but allows for additional top-mounted attachments with minimal interference. It has a side charging handle, but even that was unique. It is a folding design that keeps it out of the way and reduces the chance of snagging.

Along with the 6.8 Hybrid chambering, Sig’s LMG-6.8 can also be chambered in 7.62x51mm NATO and 6.5 Creedmoor.

You can load the LMG-6.8 on safe or fire, feed tray open or closed, with or without the loading spoon, and with the bolt forward or back. It also features a mountable magwell for the attachment of its box magazine. This makes reloading on the move a more familiar and much easier task.

The LMG-6.8 can also be chambered in 7.62x51mm NATO and 6.5 Creedmoor. This is brilliant on Sig’s part as it allows soldiers to train with and expend existing stockpiles of ammo while building up new stockpiles.

Even though it weighs less than the M249 SAW, it was easier to run because of Sig’s recoil mitigation design and engineering. While the classic position for a SAW is with the shooter prone behind it, the LMG-6.8 is light enough and ergonomically superior enough to fire offhand. This is a major advantage for combat applications.

While a based position is a better option, the ability to shoot and move with this belt-fed is a game changer. I have spent more than my fair share of time behind a M249SAW, and the LMG-6.8 is significantly better.

No Suppressing the Enjoyment

The experience was even more enjoyable because the gun was suppressed. The use of suppressors in combat has been a commonplace thing in Special Operations forever. As the big Army started entering this realm, however, they soon began to experience the gas blowback that comes with cans. They realized that this was probably none too good for your health and began searching for less toxic options.

Sig had an answer, as you have guessed. The can we ran on the gun was a Sig Next Generation Suppressor. The design reduces harmful backflow and signature that feature low flash with a quick-detach design. It performed spectacularly, and as the rounds burned through the gun like butter, I had no gas back in my face.

The SIG MMG-338 is the belt-fed option in the lineup of NGSW.

SIG LMG-6.8 Specs

Caliber: 6.8 Hybrid, 6.5 Creedmoor, 7.62 NATO
Barrel Length: 16 inches
Weight: Under 13 pounds
Receiver: Aluminum, non-reciprocating left-side charge
Magazine Capacity: 30, 50, 100, 200-round belts
Sights: 45-degree offset flip-up iron sights, optics ready
Trigger: Three-position, safe, full, semi
Suppressor: SIG SLX 68

The NGSW-R

As part of the NGSW program, Sig also developed the NGSW-R. This is a lightweight rifle built on the foundation of Sigs popular MCX system. Its features include a fully collapsible and folding stock, rear and side charging handle, free-floating reinforced M-LOK handguard, fully ambidextrous controls and quick-detach suppressor.

This platform is familiar to all soldiers and marines and will help ease the transition to a new weapon system. This is a short-stroke, gas piston rifle with both standard and left-side non-reciprocating charging handles. So, soldiers can maintain a firing grip while charging their weapon.

The ultimate plan is to provide the warfighter a lighter gun, but the NGSW-R has an uphill battle with that. Coming in between 8 and 9 pounds, it is beefier than the standard M4. This is due to an affixed suppressor and optic. While noticeable, it by no means was a dealbreaker. The tradeoff of a slight weight increase for greater accuracy and lethality is easy to take.

The NGSW-R features a folding stock for easier carry.

SIG MCX Spear Specs

Caliber: 6.8 Hybrid, 6.5 Creedmoor, 7.62 NATO
Barrel Length: 13 inches
Weight: Under 9 pounds
Receiver: Aluminum, non-reciprocating left-side charge and rear charge
Magazine capacity: 20, 25
Sights: 45-degree offset flip-up iron sights, optics ready
Trigger: Three-position, safe, semi, full
Suppressor: SIG SLX 68

The MG 338

Just when I thought my day could not have gotten any better, I was taken over to see the new Sig MG 338 belt-fed NGSW machine gun. Yes, a belt-fed machine gun chambered in .338. First introduced in 2017, it is designed to run the powerful, long-range .338 Norma Magnum (8.6x63mm) cartridge. It offers effective range significantly longer than that of 7.62×51 NATO weapons and is close to the heavier M2HB 50 BMG Browning.

The MG338 is also light, weighing less than the standard M240/FN MAG machine gun. The Sig MG 338 machine gun is a fully automatic, gas-operated, belt-fed weapon that fires from an open bolt. It uses a short-stroke piston gas system, with the piston running below the quick-detachable barrel. The gas block is provided with a manual gas regulator with two settings, for normal or suppressed use.

To reduce recoil, the bolt group is housed inside a long, tubular barrel extension, which is allowed to recoil inside the outer receiver. The gun is fed using disintegrating belts with open loops, and ammunition is push fed from the belt and into the barrel. You load it through a top opening feed cover. Belt feed direction can be easily set up by the operator to feed from the left or from the right.

The manual safety is ambidextrous, and the non-reciprocating charging handle can be set up by the user on either side of the gun. Ammunition can be fed from loose belts, or from special semi-rigid ammo pouches which can be attached to the bottom of the gun. The gun can also be fed via a flexible chute from a large-capacity ammunition can, installed on the vehicle.

True Long-Range Solution

The gun comes with iron sights and has a Picatinny rail interface on the top of the receiver for installation of various day and night sights. This 300-grain belted magnum round has recoil similar to a 7.62mm NATO cartridge yet is lethal to 1,700 meters or more.

It has been reported that even at 1,000 meters the .338NM can defeat Level III body armor while it is capable of penetrating soft-skinned vehicles, thus meeting USSOCOM’s need for a platform that could effectively bridge the gap between the M240 and its 7.62mm round and the .50 BMG. Running this gun was reminiscent of a M240B 7.62 machine gun. It provided lighter recoil, however, and was very comfortable to shoot.

The belt-fed SIG MG338, from the NGSW program, has the potential to replace the much heavier M2 machine gun. It also provides even better performance.

SIG MG 338 Specs

Caliber: 338 Norma Magnum, 7.62 NATO
Barrel: QD Barrel
Weight: Approximately 22 pounds
Receiver: Aluminum, non-reciprocating swappable left-side or right-side charging
Magazine capacity: Belt fed
Sights: Optics Ready, forward pivoting feed tray cover
Trigger: Safe, full, semi
Suppressor: SIG SLX 338

Ammo Dump

One thing that was the same across the board was Sig’s new hybrid ammo for this project. This ammo uses a traditional brass case that features a stainless-steel base. This increases the strength of the case’s primer pocket and allows for a higher pressure loading. Simultaneously, it maintains the tried and tested reliability of brass-cased ammo in sealing the weapon’s chamber.

The new round not only exceeds the performance of the M249’s 5.56x45mm NATO round, but also the M240’s 7.62x51mm NATO round. The unofficial take on the ammo was that you could load it hotter without any safety issues. The hybrid cartridge handles higher pressures to provide increased velocity and improved terminal performance.

Sig has continued to make large, bold moves in the firearms industry, and this is just another example of that. It is my opinion that Sig will eventually become a large, diverse defense contractor with a solid commercial side. I, for one, am excited about their future and look forward to what’s next!

For more information, visit SIGSauer.com.

This article was originally published in the Tactical Life October/November 2021 issue. Subscription is available in print and digital editions at OutdoorGroupStore.com. Or call 1-800-284-5668, or email subscriptions@athlonmediagroup.com.