The FN 20-100042 AR-15 barrel is built for 5.56mm NATO use with an 18 inch M16 profile and a rifle-length gas system. It uses button rifling, chrome-lined bore and chamber for corrosion resistance and improved heat-erosion durability, and an exterior matte black manganese phosphate finish.

Key features

• Chrome lined bore and chamber to help resist corrosion and heat erosion
• HPT and MPI inspection to help ensure integrity and consistency between barrels
• Button rifled construction for accurate, consistent performance
• Matte black manganese phosphate exterior finish for corrosion and oxidation resistance
• 18 inch M16 profile barrel with rifle-length gas system for consistent AR-15 cycling

Upgrade or configure your AR-15 with an FN 5.56mm NATO barrel built with chrome lining and inspection standards aimed at reliable, repeatable performance.