FN Barrel AR-15 5.56x45mm 16" M4 Contour Carbine Length Gas Port 1 in 7" Twist Hammer Forged Chrome Lined Chrome Moly Matte

The FN Barrel AR-15 16" 5.56 NATO with M4 contour, carbine gas, and 1:7 twist is a hammer-forged, chrome-lined barrel built on the same manufacturing principles that have armed U.S. military forces for over a century. FN America's cold-hammer-forging process creates a stronger, more durable bore than button-rifled alternatives—a difference that matters when you're pushing your AR hard at the range, in competition, or in the field. The chrome-lined bore and chamber resist corrosion and heat cycling, extending barrel life even through high-round-count sessions. This is a mil-spec barrel designed to work reliably in standard AR-15 receivers without fussing.

The 16-inch length and carbine-length gas system strike a practical balance: short enough for close-quarters handling, long enough to wring good velocity from 5.56 NATO rounds. The 1:7 twist rate stabilizes a wide range of bullet weights, from 55-grain varmint loads to heavier 77-grain match ammunition. M4-style feed ramps ensure smooth, reliable feeding with any quality magazine and ammunition combination. A manganese-phosphate finish protects the steel from the elements and wear, and every barrel undergoes magnetic-particle inspection at the factory to catch any hidden flaws before it ships.

If you're building or upgrading an AR carbine and want a barrel with genuine pedigree—one forged to military standards but available to civilian shooters—FN's hammer-forged design gives you confidence that you're not running a compromise. Whether you're an AR enthusiast, a shooter who values durability, or someone who simply prefers barrels with a proven track record, this is the real thing.

Key Features

• Cold-hammer-forged construction for superior durability and strength compared to button-rifled barrels
• Chrome-lined bore and chamber for corrosion and heat resistance
• M4 contour with M4-style feed ramps for reliable feeding in mil-spec receivers
• 16-inch length with carbine-length gas system for practical handling and velocity
• 1:7 twist rate stabilizes 55- to 77-grain ammunition and beyond
• Manganese-phosphate finish resists corrosion and wear
• Magnetic-particle inspected for metal integrity before shipment
• Built to military standards and proven in combat service

Specifications

Frequently Asked Questions

What receiver is this barrel compatible with?

This barrel is designed for mil-spec AR-15 receivers. The M4-style feed ramps and standard threading ensure compatibility with any standard AR-15 platform.

What twist rate is this, and what ammunition does it stabilize?

The FN barrel features a 1:7 twist rate, which stabilizes a broad range of 5.56 NATO bullet weights from 55-grain varmint rounds through 77-grain match-grade ammunition.

Why is this barrel chrome-lined, and what's the advantage?

The chrome-lined bore and chamber resist corrosion from moisture and the corrosive byproducts of firing, and they handle heat cycling better than unlined barrels. This extends barrel life and makes cleaning and maintenance easier, especially if you shoot high volume or in harsh conditions.

How does hammer-forging compare to button-rifling?

Cold-hammer-forging compresses the steel and creates a denser, stronger barrel than button-rifling does. This manufacturing method is why FN's military barrels are trusted for sustained fire and hard use—the process itself makes the barrel more durable.