Rosco Bloodline 10.50″ .300 Blackout Nitride Barrel 1:7

The Rosco Manufacturing Bloodline 10.50″ .300 AAC Blackout barrel is a heavy-profile 4150 CMV barrel with a nitride finish designed for SBR and pistol use with suppressors. It serves as a direct replacement for MK 18 platforms configured in 5.56 NATO and provides a slightly longer length to accommodate certain accessory mounting arrangements. The barrel’s specification set — including twist rate and finish — was chosen to support both subsonic and supersonic .300 Blackout ammunition where compatible. Design input from end users informed the balance between compact handling, suppressor compatibility, and consistent performance.

Key Specifications

• The barrel length is 10.50 inches.
• The caliber is .300 AAC Blackout.
• The rate of twist is 1:7.
• The barrel material is 4150 CMV.
• The finish is Nitride.
• The barrel is a Heavy Profile design.
• The marketed model name is Bloodline.
• The color/finish appearance is Black.
• Intended use is SBR and pistol use with suppressors.

Built for compact, service-oriented AR platforms, the Bloodline 10.50″ barrel pairs durable 4150 CMV construction and a nitride finish with a 1:7 twist to provide predictable stabilization across common .300 Blackout loads. Its heavy profile and finish offer durable wear characteristics and suppressor-friendly performance for users assembling SBR or pistol configurations that demand a compact, purpose-driven barrel solution.