Rosco Mfg Bl-105-M4-556-7-C Bloodline 5.56 Nato 10.50" Nitride 4150 Cmv Brl

The Rosco Manufacturing Bloodline 5.56 NATO barrel is a short-barrel rifle (SBR) and pistol-caliber carbine solution built for shooters who demand balanced dwell times and reliable cycling across different shooting scenarios. At 10.5 inches, this barrel is purpose-engineered for compact builds where standard rifle-length gas systems create reliability headaches—whether you're running suppressed, unsuppressed, or somewhere in between. Rosco took the guesswork out of SBR design by tuning gas port diameter and barrel geometry specifically for the Bloodline profile, not applying a one-size-fits-all approach to a problem that demands precision.

Built from 4150 Chrome-Moly Vanadium steel and finished in Rosco's durable nitride coating, this barrel handles the wear of frequent shooting while resisting corrosion and fouling buildup. The .750" gas block journal accepts standard AR-platform gas blocks, keeping your parts ecosystem simple and your build flexible. Nitride finishing adds hardness without the brittleness of some other coatings, which matters when you're running suppressed or pushing high-velocity loads through a compact tube.

Whether you're building a tactical truck gun, a dedicated SBR for home defense, or a lightweight patrol carbine that doesn't sacrifice on dependability, the Bloodline delivers the engineering input that came from actual military end users and community feedback. This is a barrel designed around what works, not what's cheapest to manufacture. Note that NFA regulations apply to any firearm built with this barrel—ensure your configuration complies with federal and local law before assembly.

Key Features

• 10.5" barrel length optimized for short-barrel rifle and pistol builds
• 4150 Chrome-Moly Vanadium steel with nitride finish for durability and corrosion resistance
• Gas port sizing and dwell time engineered specifically for SBR performance
• .750" gas block journal for standard AR-platform compatibility
• Designed to function reliably suppressed or unsuppressed

Specifications

Frequently Asked Questions

Will this barrel work in a standard AR-15 lower receiver?

Yes—the Rosco Bloodline uses a standard 1/2"-28 muzzle thread and accepts a .750" gas block, making it compatible with any AR-platform lower. However, firearms configured with a 10.5" barrel may be classified as short-barrel rifles under federal law and are subject to NFA registration and restrictions. Verify your intended configuration complies with all applicable federal and state laws before assembly.

Can I run this barrel suppressed?

Yes. The Bloodline barrel's gas port sizing was tuned to cycle reliably with a suppressor attached. Suppressed shooting typically increases back-pressure, which can cause cycling issues if the gas system isn't matched to the barrel—Rosco engineered this barrel with that real-world use in mind.

What finishes or coatings are available?

The Bloodline comes with a nitride finish, which provides durable corrosion resistance and hardness suitable for both suppressed and unsuppressed use.

Is this barrel suitable for a pistol build or SBR?

The 10.5" length and dwell-time optimization make it a solid choice for both applications. As noted, any firearm built as a short-barrel rifle is subject to NFA rules. Consult local and federal regulations before assembly.