The Ballistic Advantage Modern Series Barrel (brand part no. BABL556024M) is a 12.5-inch, 5.56x45mm NATO AR-15 barrel machined from 4150 chrome moly vanadium steel in a Government profile with a QPQ corrosion-resistant finish. Ballistic Advantage cuts a 1:7-inch twist rate to stabilize the full range of common 5.56 bullet weights and runs a .750-inch gas block journal on a carbine-length gas system, with a QPQ-coated M4 feed ramp extension for reliable feeding. Because a 12.5-inch barrel falls under the 16-inch federal minimum for a rifle-configured lower, all NFA/ATF rules apply to how this barrel can legally be assembled.

Key Specifications

• Chambered in 5.56x45mm NATO / .223 Remington.
• 12.5-inch barrel length.
• 1:7-inch twist rate, stabilizing heavier 5.56 bullet weights.
• Machined from 4150 chrome moly vanadium steel in a Government profile.
• Finished in QPQ for corrosion resistance.
• Includes a QPQ-coated M4 feed ramp extension for reliable feeding.
• Runs a .750-inch gas block journal on a carbine-length gas system.
• Threaded muzzle, finished in black.

Frequently Asked Questions

What caliber is this barrel chambered in? 5.56x45mm NATO / .223 Remington.

Is this barrel legal to install on any AR-15 lower? No. At 12.5 inches it is under the federal 16-inch rifle minimum, so it may only be installed on a lower configured as a pistol, or on a lower that is a registered SBR or machine gun — installing it on a non-NFA rifle-configured lower is prohibited.

What gas system does this barrel use? A carbine-length gas system with a .750-inch gas block journal.

Buy the Ballistic Advantage Modern Series Barrel

Build or upgrade a 5.56 pistol with a Government-profile barrel built for reliable feeding. Order it from our AR barrels selection at our Lubbock, Texas gun shop for fast, direct shipping.