This rifle very closely resembles the Military issue M4 but with a Free Floating Centurion C4 Rail and a Liberty Fighting trigger. Everything you need in a patrol rifle and nothing you don't. Sons of Liberty Gun Works we believe in Quality Mil-Spec or better parts. We believe there is no substitute for quality and that your gun should be built right the first time, ready for hard use right out of the box. We believe a quality Bolt Carrier Group and a quality, accurate and long lasting barrel are the heart of a Combat Grade weapon. We believe in properly tuned weapons using the correct gas system length and quality buffer system components such as Sprinco Tactical Buffer Mfg: Sons Of Liberty Gun Works