The Rosco Manufacturing Bloodline AR Barrel, .300 Blackout, 10.5 Inch, Nitride 4150 CMV (Rosco part number BL-105-HB-300BLK-7-P) was designed for compact builds run in conjunction with suppressors, giving builders a direct replacement barrel length for any MK 18-platform build currently running in 5.56 NATO. The 10.5-inch length is also a practical pick for carbines that need a slightly longer rail to comfortably run a PEQ-15, D-BAL series, or other laser aiming device. Machined from 4150 chrome-moly-vanadium steel and finished in black nitride, the barrel carries a 1:7 twist that stabilizes heavier 300 Blackout subsonic loads as well as lighter supersonic ammunition.

Key Specifications

• Chambered in .300 AAC Blackout.
• Barrel length is 10.5 inches.
• Rate of twist is 1:7, stabilizing both subsonic and supersonic 300 Blackout loads.
• Machined from 4150 chrome-moly-vanadium (CMV) steel with a black nitride finish.
• Designed as a direct replacement for MK 18-platform builds currently in 5.56 NATO.

Frequently Asked Questions

What steel and finish does this barrel use? It is machined from 4150 chrome-moly-vanadium steel and finished in black nitride.

What is this barrel designed for? Compact builds run in conjunction with suppressors, and it doubles as a direct MK 18-pattern replacement barrel.

Why might I want a 10.5-inch barrel over a shorter length? It gives carbines a bit more rail real estate to comfortably mount a PEQ-15, D-BAL series device, or other laser aiming unit.

Buy the Rosco Manufacturing Bloodline AR Barrel, .300 Blackout, 10.5 Inch, Nitride 4150 CMV

Order it from our Lubbock, Texas gun shop for an MK18-pattern 300 Blackout barrel built for compact suppressed builds. Shop more Rosco Manufacturing parts in our AR barrels category.