Diamondback 556M16M50B8R 5.56x45mm NATO 16" Black Nitride Chrome Moly Vanadium Steel Rifle

The Diamondback 556M16M50B8R is a 5.56x45mm NATO rifle barrel built for shooters who demand accuracy and reliability without compromise. At 16 inches, this mid-length gas system barrel strikes the balance most shooters want—fast enough for defensive applications, compact enough for maneuverable platforms, and accurate enough for precision shooting. Whether you're building an AR for home defense, range work, or general-purpose shooting, a quality barrel is where accuracy starts, and Diamondback barrels are manufactured to exacting standards using modern CNC equipment and premium materials.

This barrel is machined from 4150 Chrome Moly Vanadium steel and finished with Black Nitride, a proven combination that delivers excellent corrosion resistance and durability through thousands of rounds. The medium contour keeps weight reasonable while maintaining rigidity, and the 1:7 twist rate is standard for reliable stabilization across the full range of 5.56 loads. Button rifled with Diamondback's 5R M4 profile and finished with a traditional 11-degree target crown, the bore is optimized for consistency shot to shot. The 1/2x28 thread pattern accepts standard muzzle devices, and integral M4 feed ramps ensure reliable feeding whether you're using milspec components or higher-grade matched parts.

Diamondback's machining credentials span military, aerospace, and firearms industries—this isn't a commodity barrel made to a price point. It's a no-frills, purpose-built component for builders and shooters who know that barrel quality directly affects group size and long-term reliability. If you're assembling a rifle or replacing a worn barrel, a Diamondback barrel gives you the foundation to build something that will shoot straight for years.

Key Features

• 16" length with mid-length gas system—compact handling balanced with velocity and reliability
• 4150 Chrome Moly Vanadium steel with Black Nitride finish for corrosion resistance and durability
• 1:7 twist rate for stable performance across 5.56 load weights
• Button rifled 5R M4 profile for consistent accuracy
• Traditional 11-degree target crown for reliable bullet seating
• M4 feed ramps for reliable feeding with AR-platform bolts and magazines
• 1/2x28 threaded muzzle for standard AR accessories
• Medium contour balances weight, rigidity, and heat capacity

Specifications

Frequently Asked Questions

What AR-15 platforms does this barrel fit?

The Diamondback 556M16M50B8R is designed for standard AR-15 rifles using .223 Remington or 5.56x45mm NATO. The M4 feed ramps and 1/2x28 muzzle thread are milspec AR components. Confirm your upper receiver is compatible with a mid-length gas system barrel before ordering.

What ammunition does this barrel shoot?

This barrel is chambered for 5.56x45mm NATO and .223 Remington. Both cartridges are interchangeable in this barrel. The 1:7 twist rate will reliably stabilize the range of bullet weights commonly used in both calibers.

What muzzle devices can I use with this barrel?

The barrel is threaded 1/2x28, the standard muzzle thread for 5.56 AR-15 rifles. You can attach any 1/2x28 device—flash hiders, compensators, brakes, or suppressors (where legal)—directly to the muzzle.

Is this barrel suitable for precision or long-range shooting?

At 16 inches, this barrel prioritizes maneuverability and mid-range performance over extreme velocity or precision benchrest accuracy. It's accurate enough for defensive and general-purpose shooting, and many shooters find it adequate for duty-grade precision to 300 yards, but it's not a dedicated long-range barrel.