The Rosco Manufacturing Bloodline Barrel (brand part no. BL-145-GVT-556-7-M) is a 14.5-inch, mid-length 5.56 NATO barrel machined from 4150 chrome-moly-vanadium steel and finished in nitride for corrosion and wear resistance. Rosco Manufacturing designs this Bloodline variant around USASOC’s Improved Upper Receiver Group (IURG) specifications, using a longer mid-length gas system to produce a smoother gas curve and better-managed dwell time. The result is a barrel that balances speed and performance for a duty-ready AR-15 build.

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.
• Runs a mid-length gas system rather than carbine-length.
• Designed around USASOC Improved Upper Receiver Group (IURG) specifications.
• Longer gas system produces a smoother gas curve.
• Better manages dwell time for balanced speed and performance.

Frequently Asked Questions

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

What gas system length does it use? Mid-length, for a smoother gas curve and managed dwell time.

What spec is this barrel built around? USASOC’s Improved Upper Receiver Group (IURG) specifications.

Buy the Rosco Manufacturing Bloodline Mid-Length Barrel

Build or upgrade your AR-15 with a USASOC-spec mid-length barrel. Order it from our AR barrels selection at our Lubbock, Texas gun shop for fast, direct shipping.