Frag Out! Magazine
Issue link: https://fragout.uberflip.com/i/1407740
GENERAL DYNAMICS OTS & BERETTA The RM277 is a joint venture between General Dynamics Dy- namics Ordnance & Tactical Systems, Beretta and True Velocity ammunition manufacturer and is definitely a most unconvention- al proposal for NGSW and radically new. RM277 is still the most secret one too. First noticeable differ- ence is the bull-pup design even though this concept is losing popularity and the US Army was always preferring more tradi- tional solutions. According to General Dynamics claims, they were able to solve the major problems with bull-pup design such as the electromechanical trigger group. Use of the longer barrel allows to achieve the required muzzle velocity without increasing the gas pressure as in the Textron rifle. This should improve the durability and life-span of the barrel and other parts. Controls are fully ambidextrous and located over the pistol grip. Unusually, the safety switch and fire mode selector switch are separated, most probably due the internal layout of the parts. First feedback from users was negative, so we can expect a sin- gle safety/selector switch in following variants. The direction of case extraction and charging handle placement might be changed from left to right. The most unique feature of RM277 are the internal automatics which are essentially a development of SRIA (Short Recoil Im- pulse Averaging) system patented in 2012. The SRIA was used for the first time in the .338 Lapua Magnum General Dynamics LWMMG machine gun. The system is a hybrid: gas and recoil operated. It was developed to radically reduce the recoil force of such powerful rounds as 6.8 NGSW. There is nothing surprising about that as in 2012 General Dynamics already declared that SRIA might be scaled to any caliber, even 5.56 NATO. The RM277 incorporates dual firing modes, closed bolt in semi-automatic mode and open bolt in automatic mode, as it was in FG42 or MGX. In the promotional RM277 shooting videos it seems that the automatics work as declared and rifles are controllable in fully automatic or burst mode on the same level (or maybe even high- er) as in Textron one. Theoretical rate of fire is around 550 RPM. According to current trends, the only significant difference be- tween NGSW-R and NGSW-AR is the barrel, which is longer and has a thicker profile in the machine gun variant. The GD-OTS pro- posal is the only one NGSW-AR fed from box magazines instead of belts. Currently, 20 round magazines are being used and in- creased capacity ones are still in development. The ammunition for RM277 is known as .277 TVCM. It was specifically developed by True Velocity, one of the most expe- rienced polymer-cased ammunition manufacturers. The .277 TVCM rounds have a hybrid case with steel base and short- ened neck. It is being estimated that such a solution allows the pressure of 85,000 PSI or more (586MPa) without complicated feeding mechanisms as in CT fed Textron guns. The ballistic pa- rameters remain unknown for the public, but during trials with XM1186 projectile the muzzle velocity was 960 m/s and higher. 51 www.fragoutmag.com SMALL ARMS