Rosco Manufacturing Bloodline 5.56 Barrel Government Carbine 10.5"

Manufactured by Rosco Manufacturing
SKU: BL-105-M4-556-7-C
MPN: BL-105-M4-556-7-C
Manufactured by Rosco Manufacturing
7 Reviews

Out of Stock



The National Firearms Act regulates the configurations of some firearms assembled with barrels under 16” long. Know the NFA laws in your state before purchasing this item.

The AR-15 is by far the most dominant carbine on the market. To stand out, simply building 'good enough' components doesn't cut it. The Bloodline series of barrels was designed and built entirely in-house by Rosco Manufacturing with the sole purpose of providing you with a barrel that will not only outperform the competition but outlast it too.

  • 10.5" Government contour
  • Carbine length gas system
  • 1/2x28 threading with 11-degree crown
  • 1:7 twist flexible round selection
  • 41V50 Chrome Moly Vanadium steel
  • Corrosion resistant salt bath nitride finish
  • Slick nitride-finished M4 barrel extension
  • Compatible with standard .750" gas blocks
  • 5.56 NATO chamber

Rosco Manufacturing takes their barrels seriously. Rather than entrust someone else's blanks or machining, they produce every barrel from scratch, controlling every step of the manufacturing process. The Bloodline series is cut from high-strength 41V50 Chrome Moly Vanadium steel, the same stuff chosen for the rifles used by our military for its exceptional durability. Improving on the military-grade barrels, the Bloodline-series are finished with a highly corrosion resistant, low friction salt bath nitride treatment, making cleaning easier than ever. By producing these barrels entirely in house, they've also been able to tune each barrel by selecting the optimal twist rates, gas port diameters, dwell times, and materials according to the needs of each barrel.

This 10.5" barrel is machined to a balanced Government contour, offering a solid balance between rigidity and weight. The reliable carbine-length gas system ensures your rifle gets the right amount of gas to cycle even in adverse conditions. The 5.56 NATO chamber is fully compatible with .223 Remington ammunition, with a 1:7 twist rate that is perfect for heavier, precision-oriented cartridges, but is thoroughly functional with popular and less expensive bullet weights.

Rosco Manufacturing got their start producing high quality, hard-use precision rifle barrels. They have since expanded, offering their own line of serious use parts and accessories so you can assemble a rifle that doesn't just shoot good and look good, but will handle hard use as well. To top it off, they're production facility is in Central Falls, Rhode Island so you know that every component is 100% made in America, by Americans.
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Barrel CoatingSalt Bath Nitride
Barrel ContourGovernment
Barrel Length10.5
Barrel LiningSalt Bath Nitride
Barrel Material41V50 Chrome Moly Vanadium Steel
BrandRosco Manufacturing
Caliber Gauge5.56 NATO
Feed RampsM4
Gas Seat Diameter.750
Gas System LengthCarbine
Thread Pattern1/2 X 28
Twist Rate1:7
Weight19.28 Oz.

WARNING: This Product can expose you to chemicals which is known to state of California to cause Cancer and Reproductive Harm. For more information, see

Ratings & Reviews

7 reviews

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It’s amazing


By far one of the best barrels on the market. Thousands upon thousands of rounds through mine. Still looks brand new.

Bloodline, the best line.


I wanted to try the Bloodline series based upon all the great feedback on social media. I was in the middle of an AR pistol build and it came time to buy a barrel in 10.5/5.56. This thing has been AMAZING after about 2k rounds through it. Fit, finish, looks....its got it all. Don't hesitate on these (currently sold out) because you will not regret it at all. Mine has a Surefire Warcomp (closed tine) and I am shooting 1in groups at 100 yards. Not the easiest task with a 10.5in but I can do all day longgggggg.

Rosco Barrel

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If ya know, ya know. If you’re spending three times this on “higher end” namebrand barrels, you’re doing me a favor by keeping these ones in stock...

Great barrel. Great supplier

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Everything you’d expect from a top notch barrel at nearly half the price. Plus with Primary Arms amazing sales, got it at extra 10% off. Ordered on a Thursday, delivered on a Saturday. Standard shipping. In the midst of these COVID times and crazy logistics, Primary is more dependable and as fast as Amazon. Customer for life!


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Great deal on what looks like a fine barrel have not used it yet but by the quality look should be fine. Fast delivery good price.

High Quality That Won't Break the Bank

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The first time I ordered Rosco, I was shocked at the quality and how great everything looked. Many rounds later, I'm still impressed. They hold up and shoot better (and look better) than barrels three times as expensive. My go too for every build I have done since. (Side note- Multiple Bloodline Barrels I tried were VERY loose in my Vltor MUR upper- to the point that I didn't build that paticular rifle with a Rosco. Every other upper has been snug and fit great). Fast shipping and great service from PA as usual.

Superb quality / great price!

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The quality is top notch. Packaging is A+ and like always, quick shipping from PA!