Rosco Manufacturing 14.5″ M4 5.56 NATO Bloodline Barrel (1/7 Twist)

Original price was: $145.00.Current price is: $102.78.

In stock

SKU: BL-145-M4-556-7-C

Product Description

14.5″ M4 5.56 NATO Bloodline Barrel: This Rosco 14.5″ M4 5.56 NATO Bloodline Barrel was built around the M4 platform and is designed to be the next evolutionary step in the series. This barrel is perfectly suited for your next patrol or duty carbine 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-15, 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 14.5″
Barrel Weight 26.34 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






Technical Information

Barrel Twist


Thread Pitch

1/2 x 28

Catalog Location

California Prop 65 Warning

WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information visit

Customer Reviews

Based on 1 review
14.5 Bloodline Carbine gassed

I have not had a chance to install yet, nor run my bore cam down it. However upon my preliminary inspection the barrel extention & lugs are well within spec. M4 feed ramps appear very uniform & I do not forsee any issues there. no burrs or off symetry. just eye-balling down the bore, rifling looks clean crisp & even ( but I will know more after I run a cam down it ). the gas port is within tolerance. the threads are flawless & the crown is typical with minimal tooling marks. The finish was a little 'glossy' to my liking, thats O.K. going to tape off the threads, gas-port & extenion & hit it with a couple coats of flat dark grey high-temp rattle can paint. Shipped immediately (after an error on my end) & came in a box extremely well packaged (with some stickers!). Overall a 9.9 out of 10 and thats only because I have not had a chance to run it yet.