Bloodline 11.5″ M4 5.56 NATO

From: $159.00

This Rosco 11.5″ M4 5.56 NATO Bloodline Barrel is designed to be the perfect addition to any SBR or Pistol build. ALL NFA RULES APPLY!

(37 customer reviews)

Melonite Gas Tubes

Our Rosco Melonite Gas Tubes have an extremely durable Black Nitride finish that increases corrosion resistance, wear resistance, fatigue strength and cosmetic appeal. These gas tubes work great under a handguard because they are more durable than standard gas tubes. Available in pistol, carbine, patrol length, mid-length, and rifle lengths. Does not include a roll pin.

Non-Adjustable Gas Block, v2

Our v2 Non-Adjustable Gas Blocks feature the same 'Bloodline' dependability, with improvements for the modern shooter.  We added a knockout hole at the front of the gas block to aide in removing the gas tube. Also featuring improved tolerances and finishes, making the v2 Gas Block a staple for years to come.

Adjustable Gas Block

Our Rosco Adjustable Gas Block is purposely designed to be lined up perfectly with our barrels and gas ports to ensure reliable cycling every time. These Adjustable gas blocks pick up where our standard block leaves off and works perfectly for shooters that want to be able to control their gas flow for suppressed applications.

Out of stock

In stock

Bloodline 11.5″ M4 5.56 NATO: This Rosco 11.5″ M4 5.56 NATO Bloodline Barrel is designed to be the perfect addition to any SBR or Pistol build. ALL NFA RULES APPLY!

Our Rosco 5.56 (NATO) barrels are designed to meet the modern day carbine shooters requirements. We are a long way from our daddy’s “Sporter” AR, and those specs just won’t cut it anymore. From properly managed dwell times for SBR’s, to running Suppressed, or setting up a balanced patrol carbine we have incorporated your needs into our engineering. We have successfully accomplished this by picking the right twist rates, gas port diameters, and barrel materials according to the barrel we are making (not a lazy blanket method). We have also balanced input from our consumers and military end users in order to bring you the rifle barrels you need, not just the one we want to sell you.

Barrel Length 11.5″
Barrel Weight 20.82 Oz
Barrel Material 4150 CMV
Barrel Caliber 5.56
Barrel Profile




Barrel Thread

1/2 x 28

Gas Block Size


Gas System Length

Barrel Crown

11 Degree

Barrel Finish


Barrel Extension Finish


Browse all of our 5.56 NATO Bloodline Barrels >>

Additional information

Weight 1.5 lbs
Dimensions 19.5 × 2.3 × 2.2 in

Melonite Gas Tubes


Carbine Length

37 reviews for Bloodline 11.5″ M4 5.56 NATO

  1. aerialphoto7 (verified owner)

    I purchased this barrel for an AR pistol build. It was an excellent choice.
    The fit and finish are superb and the quality is world class. The sizing of the gas port is perfect for this length barrel.
    An excellent value.
    You could spend a lot more money for a barrel half as good. Buy one of these and you won’t be disappointed.

  2. CDragen (verified owner)

    Also bought this barrel for a pistol build, and I have not been disappointed. Very consistent performance even under stress. A good tight fit to the upper in installation, and as mentioned in a previous review the finishing on this barrel is excellent. Add in the economical pricing and Rosco has secured a repeat customer from me–I’ll be back for more when I need them, no second thoughts.

  3. dean Kerro (verified owner)

    Starting from opening the box I was super impressed. Like a child opening Xmas presents. The finish and packaging was astounding. Was truly blown away at how this barrel looked. So I had to put it through its paces. 1000 rounds through it using a binary trigger and it is showing no signs of stopping. My zero is still holding true and no malfunctions accept for a very dirty bcg. Super impressed will be buying all my barrels through Rosco.

  4. Albert

    I built a pistol several months back and waited to shoot it at least 6 times and over 500 rounds. This barrel has outstanding accuracy and is extremely well made. I installed a Seekins adjustable gas block on it and it shoots like butter. SMOOTH.

  5. K. Church

    I ordered this barrel for a pistol build based on an excellent review. When I received it, it was beautiful and just as I wanted. It is now mounted and can’t wait to get to the range . Great job Roscoe. Looking forward to my next build. Probably a 14.5 pistol.

  6. H

    I made a mistake in buying a Brand X 10.5″ barrel from a guy that supposedly makes them for “government” agencies, and after assembly and test firing I learned I had been “HAD!”
    I had a modest priced single-shot AR pistol that failed to cycle and cases would stick in the chamber because, I’m certain, he used a rock to cut the chamber. Boy did I feel like a dummy! (Sigh!!) At least I didn’t spend a fortune.
    I was unable to find another 10.5″ barrel of ANY brand/manufacturer in town until I called the LAST place, only to find they carried the Roscoe line but not in 10.5″…only 11.5″ at the time and their last barrel as it turned out.
    To make a long story longer, I hustled some 45 miles one way to the shop on a late Saturday afternoon (they were closing in 2 hours, YIKES!) and bought the barrel and asked to have them install it for me to save the aggravation. For a modest price they did accomodate my needs (I had an impromptu match the next morning) and I used the barrel/pistol assembly to compete the next morning.
    I wish I could tell you I placed high in standing/scores, but this 60+ year old Fart was beat fair and square by kids anywhere from 16 up to 20-somethings and didn’t feel bad. They were kind and kinda impressed that an Old Fart (who is also a Disabled Veteran) wasn’t far off the mark with MY scores. I just cannot move at lightening speed any more considering my right leg/knee is AFU.
    My point in all this is that I’m SUPER happy with my Roscoe 11.5″ Bloodline M4 5.56 barrel and its inherent accuracy as well as its modest price.
    I’m SOLD on the brand as well as the high quality. I fully intend to buy several spare barrels in various lengths for every purpose from a replacement AR Pistol up to and including a barrel for much longer range plinking, if I need to do such with an AR Platform rifle.
    I am now a Roscoe Barrels Fanboy for LIFE!
    Now excuse me while I go search for some merchandise (if you’all sell such things) that I can plaster on my gun cases, that or a Tshirt. Advertising is something I NEVER do but you folks are getting my “Cherry!” LMAO
    Keep up the GREAT work at making SUPERIOR quality barrels!!

  7. Nathan

    I bought an 11.5″ barrel made by you guys and recently went out to the range to shoot and check my zero since I usually take my AR pistol with Aimpoint Micro H-1 everywhere. I ended up hitting a 12″ gong at 400 yards with Hornady Black 223 75gr BTHP, Federal 62gr “Green Tip” and 15 year old tulammo 55gr. This was last weekend and I’m still blown away. I plan on buying another 11.5″ barrel and maybe a 16″ just to have extras when I free up some money. I have not stopped telling people I work with and friends. Hands down these are the BEST barrels Ive ever used. Thank you for a great product.

  8. Kyle Rodebush (verified owner)

    This is the second barrel I have ordered from Rosco and I could not be more satisfied, the quality control is amazing. I have ordered barrels from other companies and Rosco’s packaging is head over heels better than a lot of companies. The professionalism of this company I could not be more satisfied with.

  9. Jeff Coleman (verified owner)

    I purchased this barrel last summer. I have about 3500 rounds through it. I put it on a enhanced aero precision set with an aero gas block and tube and bcg. Its has not jammed once. I’m running a super 42 spring and I didn’t have to change the buffer weight from an h1 because rosco drilled the gas port correct. Bottom line I highly recommend rosco barrels

  10. Reuben P. (verified owner)

    Awesome fit and finish, looks like a barrel that I paid twice the money for. Shoots smooth as silk! Accurate and dependable! perfect for my truck gun build! I really appreciate the swag it’s nice!

  11. Azizes (verified owner)

    Perfect and awesome barrel ???

  12. Cam

    Love this barrel. Buying the 13.7 Wylde next week.

  13. Robert Shepard

    I’ve purchased the rosco 11.5 barrel and couldn’t be more happy. The fit was nice and tight the packaging and finish are second to none. Price is for the working class man and the accuracy is the best I’ve shot. You guys grab a jp enterprise silent capture buffer spring at an h2 weight Jesus smoothest operated / shooter I’ve touched it is worth the money bettering the experience of the 11.5 fantastic next is a 12.5 and 14.5 from rosco and I already have the receivers God bless rosco and wish you much success stay die hard . Modernwyattearp ?

  14. Steven

    Bought this for a pistol build just to see about the hype I put it in a Aero with a Bcm Bcg an it runs flawless. You can’t go wrong with Rosco now I’m gonna give the bcg a try an match it up in my next build.

  15. Rob

    Bought this barrel after seeing some of their products online was a little sceptical at first to be honest never really heard of these guys. But upon arrival the packaging itself was top notch and now that I’ve put about 2k rounds through it without any issues. I can honestly this is one of the best barrels I have. Awesome product and great customer service! Don’t hesitate buying from here.

  16. Adam

    Once I received this barrel I looked it over really good, fit and finish was awesome. Tested it out at the range today and was impressed with the accuracy! This is a quality barrel, I will definitely be buying more Rosco barrels. Love the price as well!

  17. Steve Gonzalez

    I can’t say enough good things about this product. Durable, reliable, quality product.

  18. S. Lynch

    After weeks, and weeks of research I pulled the trigger on the 11.5 along with the BCG. Those on the fence, you can bank on outstanding quality and performance. A year and a half later, 5 additional barrels later, I will continue to buy and promote Rosco over the over-priced industry giants. Rosco, hands down, is the biggest bang for your buck. Guarantee once you buy Rosco you’ll be a customer for life.

  19. Micah LaVanchy (verified owner)

    Awesome barrel! I’ve put 300 rounds through it same day I assembled it. I did not have a single malfunction using the Rosco 11.5 barrel, BCG, gas block, and gas tube. Shipping was fast, packaging was excellent, most importantly barrel is accurate took 6 shots to zero in at 50 yards.

  20. Cody Groves (verified owner)

    Bay far the best barrels when you go back and forth between suppressed and unsuppressed fire. I have (3) a 10.5” – a 11.5” and a 12.5” Rosco barrel. They all have carbine length gas systems. All (3) use a non adjustable Rosco gas block and tune. My 10.5 Rosco barrel sports a silencer-co specwar 556 and my 11.5” Rosco barrel is topped off with a Surefire 300sps can. All run flawless …. You can literally build your guns around a Rosco barrel or buy a complete upper from them. These guys figured it out. Perfect gas port size, very clean, very flat.

    Midland, TX – USA

  21. Robert Caprice (verified owner)

    Bought this barrel after hearing everyone talk about it for months on the internet. Everything was as expected and top quality from the packing quality down to the barrel finish. Only have a couple hundred rounds through it so far and it has performed flawlessly on my pistol build. I paired it with the surefire warcomp and the set up has been great so far. 100% will recommend Rosco to my buddies

  22. Hector

    The QC is unmatched. I couldn’t be happier with the barrel. It came quickly and the ordering process is so easy. Can’t wait to build another.

  23. Jeremy Wells (verified owner)

    I ordered this barrel after watching a couple videos from Garandthumb. I had a 10.5 pistol build will a lesser barrel and was just unhappy with performance and function. After installing this 11.5 barrel and tuning it in, it functions flawless. The impulse is much smoother, and I have held 3″ groups or under at 200″ yards with a red dot and no magnifier. It has shot everything I have fed it very well. With a 50 yard zero it is point at shoot at 200 with 53gr superformance. This had became my new night time coyote rifle for that reason. Great job Rosco!! Looking at a 16-18″ for a new build.

  24. Blue Davis

    This is an outstanding barrel. I purchased mine from Optics Planet. The quality is superb. I used it for a left handed AR pistol for plinking. Great accuracy. Only zeroed to 50 yards so far (I did not have a lot of time that day). Hits dead center of the target every time. I could not be happier with this barrel. If your looking for a great barrel for a pistol or sbr, I highly recommend this one.

  25. Tyler Killeen

    I researched barrels for a long time before finally deciding to purchase my 11.5″ Rosco barrel, and O gotta say I’m beyond happy with it.

    First, I love the packaging it comes in. It gives it a very classy feel, like unboxing a fine watch for the first time. The barrel itself looks amazing and I found ZERO issues with a single area. The threads are perfectly cut, the coating is even all the way around, the logo is subtle but stands out nicely, and the chamber free of any tooling marks whatsoever.

    I put my new pistol together and promtly took it to the Flying Bucket to put it through it’s paces. I put around 1000 rounds down range, and this barrel kept putting rounds exactly where I wanted despite getting progressively hotter under the hot AZ sun. I shot a mix of brass and steel cased ammo, and not a single issue.

    This is a quality barrel, and ranks right up there with the premium barrels I’ve used in the past that cost upwards of double what my Rosco cost. I’ve already ordered a new barrel to replace my 16″ rifle, and will be utilizing Rosco barrels in all of my future builds. 100% would recommend to anyone looking for quality without having to spend $250+. Fantastic product!

  26. agarbus (verified owner)

    This barrel is amazing. I’ve had my barrel for a little over a year now before making this review. So let’s get to the point the barrel is amazing it’s accurate, durable and reliable. If you need to send freedom seeds down range with absolute certainty it will hit the target this is your barrel. I’ve put a hard 2500 rounds through this barrel. I only recently took off the barrel to some repairs to the upper and when I inspected the barrel the rifling is still perfect the gas port a little worn with the finish from a misaligned gas block. The attention to detail in this barrel is amazing from the finish to the lettering on the barrel. Through more shooting I will be able to tell you I’m not worried about this barrel letting me down

  27. Kyle (verified owner)

    Great barrel! I bought for a ar pistol build, looks great and at 50yards with red dot I’m shooting 1.5 inch groups.

  28. Joseph Scott

    I purchased my first barrel from here a little over a year ago after Flannel Daddy told me to. I purchased two 10.5” because I figured one couldn’t last that long. Still haven’t gotten to that second barrel yet, the first one is still just as amazing as it was it’s first run. Ended up going with the 11.5” this time for a new build and I’m just blown away with the machining of these barrels. The cost made me question the quality, but after owning a few bloodline barrels, I suggest buying several before they wise up and realize I’d pay double the price for these… and because Flannel Daddy told me to.

  29. Floppyfinger

    Worth the wait! I don’t buy crap. Got everything except the handguard from BDU. Paired it with a SLR rifleworks gas block. It does what it’s supposed to do. I can’t outshoot the Rosco 11.5” It loves Black Hills mk262

  30. Brian Green (verified owner)

    I’ve run this barrel for a while now. Suppressed and unsuppressed. My buffer setup is a springco blue with h2. It cycles 223 with and without my can. I just purchased another barrel to keep on the parts shelf. I would highly recommend!

  31. Michael TeHira (verified owner)

    I own every length from 10.5 to 16″ of Rosco barrels and I’m extremely pleased with all of them, from fit n finish to packaging, all top notch. Just waiting on my order to be completed for the 13.7 pure. AND stock of the threaded glock barrel and I should be good for a while. All completed barrels paired to Aero enhanced uppers and sit on either Radian or LMT Mars L lowers, my go to builds.

  32. Sam Houston (verified owner)

    Have many Rosco BlL’s. Pud for pound dollar for dollar there is no better buy. These are all sub MOA bbls with good ammo, bbl life is extremely good and God Forbit you shoot it out, you dont need to take out a second mortgage to get a new one.

  33. George Hollis (verified owner)

    This is my 4th Rosco barrel and they are one of my favorite to date, super accurate and durable, awesome fit and finish

  34. George Hollis (verified owner)

    This is my 4th Rosco barrel and they are one of my favorite to date, super accurate and durable, awesome fit and finish

  35. George Hollis (verified owner)

    This is my 4th Rosco barrel and they are one of my favorite to date, super accurate and durable, awesome fit and finish . Would definitely recommend

  36. Ranger74**

    I bought this barrel around June 2021 from a local shop here in NC. I’ve been able to run a lot of rounds through it and can say with absolute confidence that this barrel is well worth the money. It is accurate, properly gassed, and has excellent fitment to the upper receiver that it is installed in. I’m just now writing a review for this since I just purchased the 13.95 inch Bloodline barrel and I can’t wait to to see how well it does. Rosco makes solid products, so you can buy with confidence.

  37. Nicholas Elwell (verified owner)

    The barrel extension on mine had a little bump/protrusion that scratched up the inside of my upper receiver pretty bad. I’ve notified Rosco and I’m returning the barrel. They are sending me a replacement, hopefully this one gets GC’d, but my receiver is still scratched up.

Add a review

Your email address will not be published. Required fields are marked *