The Faxon Firearms Duty Series 15A58R20NGQ delivers a precision-built 20-inch 5.56x45mm NATO AR-15/M16 barrel featuring a Target Crown and a corrosion-resistant QPQ black nitride finish on 4150 steel, created for absolute reliability in field or range scenarios. This 20" barrel uses a 1:8" twist and button rifling to optimize performance with a broad spectrum of 5.56 ammunition, promoting stable muzzle velocity and tight groups across practical distances. The robust construction and finish are designed to withstand rigorous use while maintaining dimensional integrity under heat, making it a dependable choice for hunters, precision shooters, and tactical enthusiasts alike. The Duty Series embodies Faxon Firearms commitment to quality machining and exacting tolerances, ensuring a clean bore for easier cleaning and consistent accuracy after long strings of fire. Its compatibility with AR-15 and M16 platforms allows for straightforward installation on builds seeking a long-range, high-performance barrel without compromising durability. For shooters prioritizing repeatable accuracy, enhanced corrosion resistance, and a proven platform, this barrel represents a purpose-driven upgrade that pairs well with quality uppers, bolts, and handloads to achieve dependable, repeatable results.