The Diamondback DB Barrel (brand part no. DB308R18M50B10-R) is an 18-inch .308 Winchester replacement barrel machined from 4150 chrome moly vanadium steel and finished in black nitride for corrosion resistance and long service life. Diamondback Firearms cuts this barrel with a 1:10-inch twist rate and a rifle-length gas system, giving it the reach needed for consistent long-range accuracy on a .308 AR build. Whether you are replacing a worn barrel or finishing a fresh build, this barrel drops in as a direct upgrade.

Key Specifications

• Chambered in .308 Winchester.
• 18-inch barrel length for a rifle-length gas system.
• 1:10-inch twist rate, matched to common .308 bullet weights.
• Machined from 4150 chrome moly vanadium steel for strength and heat resistance.
• Finished in black nitride for corrosion and wear resistance.
• Runs a rifle-length gas system for smoother, longer dwell cycling.

Frequently Asked Questions

What caliber is this barrel chambered in? .308 Winchester.

What gas system length does it use? A rifle-length gas system.

What is the barrel’s finish? Black nitride over 4150 chrome moly vanadium steel.

Buy the Diamondback 18-Inch DB Barrel

Replace a worn barrel or finish your .308 build with a durable, nitride-finished upgrade. Order it from our AR barrels selection at our Lubbock, Texas gun shop for fast, direct shipping.