The Diamondback Firearms 16-Inch AR-15 Barrel (brand part number DB556C16MF50B8-R) is cut to an M4 contour and chambered in 5.56x45mm NATO, machined from 4150 chrome-moly vanadium steel for heat resistance and long service life. Diamondback finishes the barrel in black nitride, a coating that adds corrosion resistance and superior heat dissipation over sustained strings of fire, and cuts a 1:8-inch twist rate that stabilizes a wide range of 5.56/.223 bullet weights. Precision-crafted to meet the rigorous demands of duty and range use, it’s built for a shooter looking to rebarrel or build a reliable 16-inch AR-15 upper.

Key Specifications

• Cut to an M4 contour profile.
• Chambered in 5.56x45mm NATO.
• Measures 16 inches in barrel length.
• Cut with a 1:8-inch twist rate.
• Machined from 4150 chrome-moly vanadium steel.
• Finished in black nitride for corrosion resistance.
• Engineered for superior heat dissipation under sustained fire.
• Built for consistent, shot-to-shot precision.
• Suited to both duty and recreational range use.

Frequently Asked Questions

What twist rate does this barrel use? 1:8 inches, stabilizing a wide range of 5.56/.223 bullet weights.

What contour is this barrel? M4 contour, 16 inches long.

What finish does it use? Black nitride, for corrosion resistance and heat dissipation.

Buy the Diamondback Firearms 16-Inch AR-15 Barrel – M4 Contour, 5.56x45mm NATO, Black Nitride

Build or rebarrel your AR-15 with a precision-cut, heat-treated barrel. Order it from our Diamondback Firearms lineup, part of our AR barrels selection, at our Lubbock, Texas gun shop for fast, direct shipping.