FN 36423 AR-15 Barrel 5.56x45mm NATO 18″ Rifle-Length

Manufactured by FN, the 36423 AR-15 barrel is a cold hammer-forged component produced from high-grade Chrome Moly Venadium steel. It is chambered for 5.56x45mm NATO and configured with an 18 inch profile using a rifle-length gas system. The bore and chamber are chrome-lined to improve resistance to corrosion and heat erosion, and the exterior receives a matte manganese phosphate finish. M4-style feed ramps and a standard AR-15 barrel extension are incorporated for consistent feeding.

Key Specifications

• The barrel is chambered for 5.56x45mm NATO.
• The barrel length is 18 inches configured with a rifle-length gas system.
• Barrel type is specified as Rifle Length.
• Construction uses cold hammer forging from Chrome Moly Venadium steel.
• The bore and chamber are chrome-lined to resist corrosion and erosion.
• The external finish is manganese phosphate in a matte black appearance.
• The barrel includes M4-style feed ramps and a standard barrel extension for reliable feeding.
• Model designation is listed as AR-15.
• The source data lists a weight of 2.2 (unit not specified in source data).

This FN 36423 barrel is engineered for durability and long service life, combining cold hammer-forged construction, chrome-lined bore and chambering, and a corrosion-resistant finish. Its rifle-length gas configuration and M4-style feed ramps make it suitable for full-length AR-15 builds where reliability and longevity are priorities.