RM277

Weapon Information

The RM277 is a bullpup rifle and automatic weapon system developed by True Velocity and LoneStar Future Weapons for the U.S. Army’s NGSW program. Built around the high-pressure 6.8 TVC composite-cased cartridge, it aims to deliver improved lethality, extended range, and reduced system weight compared to legacy 5.56×45mm platforms.

Weighing approximately 9 lbs, the RM277 uses a 22-inch barrel within a compact bullpup layout, measuring 29.1 inches collapsed and 32.5 inches extended. This configuration maximizes muzzle energy without increasing overall length. The weapon family includes both rifle and automatic variants built on a common architecture, each optimized for their respective roles through different operating modes and barrel configurations.

Key features include: Gas and recoil operated system with SRIA for reduced recoil, Closed-bolt rifle (RM277-R) and open-bolt automatic (RM277-AR) variants, Fully ambidextrous controls, Tool-less field-strip barrel-change system, Magazine or drum feeding capability, Configurable left/right ejection with soft forward case ejection, Non-reciprocating charge handle with charge-on-safe capability, Modular polymer chassis suitable for optics and mission accessories.

Although not selected during the NGSW program, the RM277 showcased forward-looking concepts such as composite-cased ammunition integration, a long-barreled bullpup architecture, and advanced recoil-mitigation technology. Its dual-mode firing system, flexible ergonomics, and lightweight construction reflect a modern approach to creating compact, high-energy infantry weapons.

Weapon Specifications: 

• Caliber: 6.8 TVC  
• Barrel Length: 22 inches  
• Firing Modes: semi-auto, full-auto (variant-dependent)
• Rate of Fire: 500-600 rounds/min  
• Effective Range: ~600 meters  
• Years in Production: 2019 – Present  
• Country of Origin: United States