Bloodline 12.5” 5.56 NATO


This 12.5” Rosco barrel is designed to bridge the gap between SBR-Pistol and/ or RECCE platforms and delivers amazing precision performance for its compact size. It is the perfect addition for the person attempting to create the ultimate intermediate patrol platform.

(16 customer reviews)

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This 12.5” Rosco barrel is designed to bridge the gap between SBR-Pistol and/ or RECCE platforms and delivers amazing precision performance for its compact size. It is the perfect addition for the person attempting to create the ultimate intermediate patrol platform.

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 product you need, not just the one we want to sell you.

Barrel Length 12.5″
Barrel Weight 21.79oz
Barrel Material 4150 CMV
Barrel Caliber 5.56
Barrel Profile




Barrel Thread

1/2 x 28

Gas Block Size


Gas System Length

Carbine 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

16 reviews for Bloodline 12.5” 5.56 NATO

  1. Shane Bertrand (verified owner)

    This is my 4th barrel from Rosco. Customer service, fit, finish, accuracy, durability, etc have all be fantastic every single time I have purchased anything from them. I’ve been running a 10.5 for a while now and can’t wait to see what this 12.5 will do. #barrelgang

  2. Dan M.

    Always wanted to get around to building a Mini Recce and the 12.5” barrels that were out there lacked in performance from what I saw.

    My 14.5” Bloodline performed soo good that I decided to give this 12.5” a go, I could not be happier. I’ve been seeing 1” groups on the regular at 100 yards with 77gr TMK’s. Hope to push it out to 500 yards soon and see what it does!

  3. Dogsoldier (verified owner)

    This is my second barrel from Rosco and I don’t see myself buying from anyone else. I just took my 12.5 build out for the first time today and shot 200 rounds. Not many at this point but enough to know I made a good purchase. I have over 2k on my 14.5 Purebreed and I still get to show off its accuracy. I can’t wait to train with my teammates to show this one off also. Well balanced with consistant accuracy. It’s already my favorite.

  4. @m4gunny_ (verified owner)

    I ordered the 12.5” bloodline, while I haven’t hit the range with it I can speak to the physical quality and fitment of the parts. I got the barrel, the low pro gas block and the melonite tube. All of the fit and finish was perfect, professionally packaged and Rosco makes a product you can see the quality in by it laying on the table. I will be ordering more in the future. New favorite company to deal with. “Maybe” you can get better barrels, but for the price of the bloodlines….. goodluck matching the Roco quality to anyone else’s low price. Best “bang” for your buck I’ve seen in AR parts. Thank you guys for making a solid affordable product that will last and do what it should.

  5. Cory Yilmaz (verified owner)

    Very happy with my new rosco mfg barrel!

  6. MICHAEL MORGAN (verified owner)

    With some prompting from my son, I ordered this barrel after having problems with another 12.5″ barrel from a well known manufacturer. After several hundred rounds, I am very happy with this barrel from Rosco. The finish is very nice and this is easily the most accurate barrel within this price range. Very impressed… much so, that I just ordered another Bloodline barrel in 300BLK.

  7. Robert Elliott

    Received the barrel a week or ten days ago. I’ve been able to get it to the range a few times, about 250 rounds so far. Barrel runs great normal and suppressed. With green tip ammo it was just over an MOA. Using 1-4 optic. With MSR Fusion Ammo 62 grain, it stayed under the MOA mark. I haven’t got to shoot any heavier loads yet but I’m expecting good things. Love the barrel, would highly recommend.

  8. bill wheat (verified owner)

    AWESOME!!!!! Will run anything i put in it!

  9. Cory Haworth (verified owner)

    Haven’t tried my 12.5 barrel yet but out of the box the quality of the barrel is pristine.

  10. Kris Rodriguez (verified owner)

    Better than what I had expected with the 12.5″ and for my first build I think I made the right purchase. Shot around 250 rounds and every shot was dead on. Love this barrel and I look to ordering more in the future builds I make.

  11. Nathan Kaiser (verified owner)

    This barrel is amazing and a one of a kind product! I would recommend this barrel to anyone that is either building your own AR or just upgrading!

  12. Angelo

    Super fast shipping, awesome fit, can’t wait to take it to the range on my SBR!!

  13. Justin Duarte (verified owner)

    This is my second Bloodline barrel from Rosco and I couldn’t be happier. First one I purchased was the 10.5” and now the 12.5” for a new build and the quality is up there with the best. Definitely a customer for life

  14. rlademann83

    Rosco never fails to impress, the packaging alone is a indicator of quality. I did pick it up at BDU and saved a few bucks. Lands and grooves look like perfection. 4 stars only
    because I’ve yet to break it in due to covid19 range closers but doubt it’ll disappoint. Keep up the fine work Rosco!

  15. Brandon Thomas

    I have picked up two 12.5” Bloodline Barrels from Rosco specifically from Primary Arms. I enjoy my first one so much i bought the second one for my second AR Pistol build as i want that compact but RECCE style rifle as it fits my needs. Definitely grab one if you are looking for a 12.5” hard use barrel.

  16. Connor (verified owner)

    Fantastic fit, well machined! Shoutout to flannel daddy for mentioning it in one of his videos, thats how I found out about Rosco!

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