General Dynamics' Next Generation Squad Weapon – The RM277

Matthew Moss
by Matthew Moss

General Dynamics have closely guarded their Next Generation Squad Weapon prototypes, despite my best efforts they stuck to their guns and saved the big reveal for this year’s AUSA Exposition in Washington, D.C.There have been murmurings that their submission would be a bullpup for sometime and it has now been confirmed, meet the General Dynamics RM277.

The RM277 takes its name from the inch equivalent of the US Army’s desired 6.8mm (or .277in) round. General Dynamics won’t be releasing a press release on the rifle as it isn’t their policy to do so during an active, open competition but they did share some information on the new weapons with TFB.

Unlike both SIG Sauer and Textron, General Dynamics have opted for a common architecture for their weapons with both using the same action, feed, layout and basic design – it appears that the Automatic Rifle (AR) has a longer, and fluted, barrel.

The weapons use what General Dynamics’ describe as a ‘gas and recoil operated, impulse averaged, air cooled’ system. With both the rifle and AR being magazine fed from box magazines – this again is a departure away from rival designs, with both Textron and SIG Sauer both utilising belt feeds. The magazines appear to be proprietary, likely 20-round capacity, with what appears to be a pair of metal over-insertion tabs. If we look closely we can make out Lancer’s ‘AWM’ or Advanced Warfighter Magazine logo on the side of the magazine.

General Dynamics' NGSW-AR and NGSW-R prototypes (GD-OTS)

In the photo above we can see both weapons in FDE, both equipped with suppressors from another of General Dynamics’ partners, Delta P design, known for their innovative designs including 3D printed cans. The suppressor appears to use their flow through design. General Dynamics note that the suppressor will last the life of the barrel it is mounted on and that the design “minimizes flash and reduces sound levels to less than the requirement”. They also confirm that their prototypes are within the US Army’s weight requirements.

The weapons use standard AR-15 compatible pistol grips with an ambidextrous safety selector positioned as in the AR-15/M16/M4. This retains some familiar features from weapons soldiers will already be familiar with, however, semi or fully-automatic selection is done by a laterally sliding selector just above the safety. The prototypes appear to have stamped aluminium upper receivers and forends with two prominent take down pins, one just in front of the pistol grip assembly and the other in the rear of the receiver. There is a 12 o’clock picatinny rail and numerous MLOK mounting points. The design moves away from the AR-15/M16’s classic T-charging handle and instead has a side-switchable charging handle located above the barrel. It is unclear if the direction of ejection can be switched, but this seems a probable feature. The AR prototype has a slick-looking bipod which is angled to attach onto the forward-angled forend and folds up quite flush with the bottom of the weapon (see photo below). There does not appear to be any means of adjusting the weapons’ length of pull.

General Dynamics' NGSW-AR with bipod folded, also mounted are 45-degree BUIS and an ELCAN SpecterDR 1-4x and an additional red-dot. (GD-OTS)

As mentioned earlier the weapons use a ‘gas and recoil operated’ system, while General Dynamics have not gone into detail of how this works they do mention some interesting features. Publicity materials describe “shot recoil, impulse averaging technology” which minimises recoil loads and weight and enables controllable automatic fire – which is abundantly demonstrated in their promo video below. This is said to give the weapons reduced felt recoil optimal for accurate long range engagements. Perhaps the most interesting feature, however, is that the weapons use a dual firing system – firing from a closed bolt when in semi-auto and from an open bolt when in full-auto, to aid cooling.

General Dynamics were kind enough to send us their promo video which introduces their NGSW prototypes in pretty spectacular fashion, check it out below:

As we already know the rifles are chambered in a polymer-cased round developed and manufactured by True Velocity. We now know that GD-OTS and TV have designated this cartridge the 277 TVCM. Which they say is “designed specifically for use of Composite Materials” and uses an “Advanced Composite Cartridge Case” which minimizes weight and utilises ‘Compacted Propellant Technology’ to minimise case volume and weight. They claim that the round is 30-40% lighter than conventional brass ammunition and “produces logistical cost-savings while simultaneously lightening the soldier’s load, increasing firepower and improving operational effectiveness.”

True Velocity and General Dynamics’ 6.8mm polymer hybrid round – the 277 TVCM (True Velocity)

Reduced heat transfer is another positive of the 277 TVCM round which General Dynamics emphasis, stating that the round’s composite case insulated the chamber and bolt face thus reducing wear on weapon components. General Dynamics also cite improved accuracy due to manufacturing processes which ensure ” consistent case and precise powder drop, producing exceptionally consistent pressure and muzzle velocities.” Another selling point of the round that they stress is that in-theatre, on-demand manufacture is ‘a reality’.

In terms of operator health and environmental impacts General Dynamics note that the composite round eliminates the use of heavy metals which have adverse effects on soldiers and to answer environmental concerns they say that the cases are 100% recyclable, with the steel base allowing magnetic retrieval during training exercises.

Submitting a bullpup weapon system is certainly a bold move, especially when other competitors have opted for conventional layout weapons, and the US military has never previously been interested in the bullpup concept. I’m looking forward to seeing how General Dynamic’s RM277 fares during the upcoming trials.

Matthew Moss
Matthew Moss

Managing Editor: & Overt Matt is a British historian specialising in small arms development and military history. He has written several books and for a variety of publications in both the US and UK. Matt is also runs The Armourer's Bench, a video series on historically significant small arms. Here on TFB he covers product and current military small arms news. Reach Matt at:

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