The REPR Rapid Engagement Precision Rifle 7.62x51mm NATO 16 Inch Spiral Fluted Barrel Threaded 5/8×24 Skirmish Sights Magpul UBR Adjustable Stock Cerakote Flat Dark Earth Finish Black Furniture 20 Round. Self-regulating, short-stroke gas piston operating system. Rear mounted charging handle. Forged lower receiver with fully ambidextrous controls (magazine release, bolt catch and release, and selector. Monoforge upper receiver. LWRCI tunable gas block for precision adjustments. Cold hammer forged, spiral fluted barrel with black nitride treatment for durability. Barrel threaded at 5/8×24 tpi. 1:10 inch right hand twist rate. Geissele SSA-E trigger. Magpul UBR adjustable stock; Magpul MOE+ grip. LWRCI 12.5 inch modular rail system with removable top rail. LWRCI Skirmish back up iron sights. Ultra muzzle brake. Capable of sub MOA accuracy. Chambered in 7.62x51mm NATO.