Diamondback 5.56 NATO 16" M4 Contour Black Nitride 4150 Chrome Moly Vanadium Steel OEM Replacement Barrel

If you're building or rebuilding an AR-15 platform rifle, a quality barrel is where precision starts. The Diamondback 5.56 NATO 16" M4 Contour Black Nitride 4150 Chrome Moly Vanadium Steel OEM Replacement Barrel gives you a modern, durable tube that meets the performance standard of factory-original AR components—without the factory price tag. Built from 4150 chrome moly vanadium steel and finished in black nitride, this barrel is engineered for reliability across everything from range days to hunting and tactical work.

The M4 contour profile is the working standard for modern 5.56 rifles: it's lighter than a government profile but stiff enough for accuracy, and it plays well with standard rail systems and handguards. At 16 inches, you get a balance that works in the field—enough velocity for duty and hunting rounds without the length penalty if you're running an 80-series lower or short-barreled platform. The 4150 steel and nitride finish mean you're not babying it on the gun; this barrel is built to run.

Whether you're swapping a worn-out factory barrel or assembling your own upper, this is a straightforward, no-nonsense component from a maker who understands what shooters actually need. Drop it in, headspace it, and get to work.

Key Features

• 16-inch barrel length for balanced velocity and handling
• M4 contour profile—lightweight yet rigid, ideal for modern AR builds
• 4150 chrome moly vanadium steel construction for durability
• Black nitride finish for corrosion resistance and easy maintenance
• 5.56 NATO chamber—compatible with standard .223 Remington and 5.56 ammunition
• OEM replacement-grade fit and finish

Specifications

Frequently Asked Questions

Will this barrel work with my AR-15 upper receiver?

Yes. This is a standard 5.56 NATO barrel with OEM-spec dimensions and headspace. It will fit any mil-spec AR-15 upper receiver. You'll need to verify headspace during assembly using a headspace gauge set—standard practice for any barrel replacement.

What's the difference between 5.56 NATO and .223 Remington?

A 5.56 NATO chamber safely fires both 5.56 NATO and .223 Remington ammunition. The difference is in how the cartridges are specified; a 5.56 chamber has slightly tighter specs to safely handle both. Your rifle will run both rounds reliably.

Is this barrel suitable for hunting?

Yes. The 16-inch M4 profile barrel is a practical choice for hunting applications where a modern carbine platform is appropriate. Ballistics and accuracy will depend on your ammunition, optics, and shooting skill.

Do I need any tools to install this barrel?

You'll need a barrel wrench, upper receiver vice block, and a headspace gauge set to properly install and check the barrel. Assembly should be done by someone experienced with AR-15 builds or a qualified gunsmith.