Stag 15 Tactical Rifles are chambered in 5.56 NATO and built around a 16" barrel with a 1/7 twist rate. They use an M16 bolt carrier group, Stag 13.5" M-LOK Handguard and Magpul furniture. These rifles have an A2 Flash Hider to reduce muzzle flash and a mid-length gas system, that is combined with a low-profile gas block, which provides reliability under any condition. The free-floating Stag 13.5" M-LOK Handguard features a slim, lightweight profile that offers increased ergonomics, maximum airflow, and modularity while continuing to provide the utmost strength and durability. The handguard provides an uninterrupted picatinny rail along the top which allows room for sights, optics and accessories the shooter may require. The Quad option on the handguard adds picatinny sections as part of the handguard on the muzzle end.