The FN 36420 is a 14.7-inch cold-hammer-forged 5.56 NATO barrel for AR-15 and M16-pattern builds. Its M16A2 / Government profile, carbine-length gas system, 1:7 twist rate, and chrome-lined bore and chamber make it a strong choice for a durable general-purpose carbine, clone-inspired build, or hard-use rifle configuration.
FN manufactures this barrel from proprietary high-grade chrome moly vanadium steel and uses cold hammer forging to create a robust barrel suited to long service life. The chrome-lined chamber and bore help resist corrosion and heat erosion while supporting dependable chambering and extraction. Magnetic-particle inspection adds another layer of quality control before the barrel leaves the factory.
The 14.7-inch length gives builders a compact profile while leaving room for an appropriately sized, permanently attached muzzle device in configurations intended to meet applicable barrel-length requirements. The barrel uses a .750-inch gas-block journal, 1/2x28 muzzle threads, and an M4 barrel extension with M4 feed ramps for compatibility with common AR-15 build components.
Whether you are replacing a worn barrel, assembling a durable 5.56 NATO upper, or building a traditional M16A2 / Government-profile carbine, the FN 36420 provides a premium factory barrel foundation. Always confirm final headspace, gas-system fitment, muzzle-device bore clearance, and compliance of the completed firearm configuration before firing.
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