The Rosco Manufacturing Bloodline Barrel (brand part no. BL-145-M4-556-7-C) is a 14.5-inch, 5.56 NATO barrel machined from 4150 chrome-moly-vanadium steel and finished in nitride for a durable, corrosion-resistant M4 carbine build. Rosco Manufacturing cuts the Bloodline with an M4 barrel contour and a 1:7 twist rate suited to the full range of common 5.56/.223 bullet weights, positioning it as a next-generation option for patrol and duty carbines built on the M4 platform.

Key Specifications

• Chambered in .223 Rem/5.56 NATO.
• Measures 14.5 inches in length.
• 1:7 twist rate.
• Machined from 4150 chrome-moly-vanadium (CMV) steel.
• Finished in nitride for corrosion and wear resistance.
• Cut with an M4 barrel contour.
• Sized for a carbine-length gas system.
• Built for patrol and duty carbine use.

Frequently Asked Questions

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

What is the twist rate? 1:7.

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

Buy the Rosco Manufacturing Bloodline Barrel

Build or upgrade your M4 carbine with a nitride-finished 14.5-inch barrel. Order it from our AR barrels selection at our Lubbock, Texas gun shop for fast, direct shipping.