FN AR-15 5.56x45mm NATO 14.70in M4 Chrome-Lined Barrel

FN’s 20-100405 AR-15 barrel is a cold hammer-forged component chambered in 5.56x45mm NATO and finished in matte black manganese phosphate. It is produced from highgrade Chrome Moly Venadium steel and is magnetic particle tested after forging to confirm structural integrity. The bore and chamber are chrome lined to resist corrosion and heat erosion, improving service life and reliable chambering and extraction. The barrel carries an M4 profile with a carbine-length gas system and M4-style feed ramps for consistent feeding.

Key Specifications

• The caliber is 5.56x45mm NATO.
• The barrel length is 14.70 inches.
• The profile is M4 Profile.
• The gas system is Carbine Length.
• The barrel construction is cold hammer forged.
• The bore and chamber are chrome lined.
• The material is highgrade Chrome Moly Venadium steel.
• The external finish is manganese phosphate (matte black).
• The barrel includes M4-style feed ramps and barrel extension for consistent feeding.

Built to deliver long service life and consistent performance, this FN AR-15 barrel pairs cold hammer-forged construction with chrome lining and a corrosion-resistant finish. Its M4 profile and carbine-length gas system make it a versatile option for range use, competition, and professional applications where durability and reliable operation are priorities.