Advanced modular piston-operated lightweight one-piece upper receiver magazine fed carbine. Incorporates unique articulating link piston (ALP) operating system that reduces the inherent stress in the piston stroke by allowing for deflection and thermal expansion. Specifically designed for ease of cleaning disassembly and assembly of parts. Weight: 6.89 pounds. Overall Length – stock retracted: 32 inches stock extended: 35.5 inches. Rate of fire: 700-950 RPM. Rifling: 1:7 inch right hand twist. Effective range: 600 m.