ROBUST CONSTRUCTION - The Nightforce X-Treme Duty Steel Base is crafted with precision CNC machining; This meticulous process guarantees optimal rail dimensions, as the base is formed from a single billet of steel; This scope mounting base is also Mil. Std. 1913/Picatinny Styled RELIABLE FIT - Engineered to match the receiver contour, this steel base by Nightforce is ready to meet avid shooters' needs and guarantees a straight and true alignment; This critical feature enhances overall performance and reliability, providing a solid foundation for your optics FUNCTIONAL DESIGN - The base is designed with scallops on the side; This adds to the functionality of the base, ensuring smooth operation in every scenario; NOTE: Clean all mating surfaces thoroughly before mounting. Use a torque wrench and do not exceed recommended torque values ESSENTIAL STABILITY - The Nightforce steel base includes an integral recoil lug machined into the bottom; This precision-fit lug not only provides stability but also prevents any movement of the base during recoil; It further eliminates stress on mounting screws, contributing to the longevity of the setup VERSATILE CONFIGURATIONS - Choose from various configurations, including a 20 MOA taper and a 40 MOA taper, catering to different shooting requirements; The base is available in both one-piece and two-piece setups, accommodating both Short and Long Action gun models