The Diamondback 16-Inch 5.56 Carbine Medium Contour Barrel (brand part no. 556C16M50B9) is a 16-inch AR15 barrel chambered in .223 Rem/5.56 NATO and built around a carbine-length gas system. Diamondback Firearms has been developing AR15 and concealed-carry pistol platforms since 1989, and this barrel reflects that same focus on efficient, no-compromise components. It runs a medium contour profile that balances weight forward of the receiver with enough mass for sustained shooting, and it wears a black finish to match standard AR15 furniture. A 1:9 twist rate handles the common range of 5.56/.223 bullet weights well. It is a straightforward, direct-fit option for building or refreshing a carbine-length AR15 upper.

Key Specifications

• Chambered in .223 Rem/5.56 NATO for standard AR15-pattern ammunition.
• Measures 16 inches in overall barrel length.
• Runs a carbine-length gas system, matched to a standard carbine handguard.
• Machined with a medium contour profile for a practical weight balance.
• Carries a 1:9 twist rate suited to a broad range of 5.56/.223 bullet weights.
• Finished in black to match standard AR15 furniture.

Frequently Asked Questions

What gas system does this barrel use? A carbine-length gas system, matched to its 16-inch length and medium contour.

What twist rate does it have? A 1:9 twist rate, which stabilizes a broad range of common 5.56/.223 bullet weights.

Buy the Diamondback 16-Inch 5.56 Carbine Medium Contour Barrel

Order the Diamondback 16-Inch 5.56 Carbine Barrel from our Lubbock, Texas gun shop for a direct-fit upgrade to your AR15 barrel setup. As a bare barrel, it ships direct with no FFL transfer required. Add it to your cart for fast, insured shipping direct to your door.