FN 20-100038 AR-15 5.56 NATO 14.7″ Mid-Length Chrome-Lined Barrel

This FN 20-100038 AR-15 barrel is a factory-built replacement or upgrade option for rifles chambered in .223 Rem / 5.56 NATO. It is button rifled and produced from U.S.-sourced Chrome Moly Venadium material to Mil-B-11595E standards. Each barrel is High Pressure Tested (HPT) and Magnetic Particle Inspected (MPI) to ensure consistency and structural integrity. The bore and chamber are chrome lined to resist corrosion and heat erosion for improved service life and reliable operation.

Key Specifications

• The caliber is .223 REM / 5.56 NATO.
• The barrel length is 14.7″.
• The profile is M16 profile for standard feed geometry.
• The gas system is Midlength.
• The finish is Manganese Phosphate.
• The bore and chamber are Chrome lined.
• The material is Chrome Moly Venadium per Mil-B-11595E.
• The twist rate is 1 in 7″ RH Twist.
• The NFA thread pattern is 1/2×28.
• The listed weight is 1.85.

Built to FN’s factory inspection and test standards, this barrel provides a durable, serviceable platform component for a variety of AR-15 use cases where consistent feeding and long-term bore life are priorities. The combination of button rifling, chrome lining, and a Manganese Phosphate finish delivers corrosion resistance and dependable function in field and range environments.