Colt M4 Commando 11.5 inch 5.56mm Heavy Barrel Assembly w/ Low Profile Gas Block

$320.00 $250.00
(16 reviews)
Current Stock:

Factory Colt M4 Commando heavy profile, 11.5 inch, 5.56x45mm NATO, carbine length gas system barrel. Complete barrel assembly features M4 feed ramp, barrel nut, low profile gas block, and is threaded 1/2-28 for your choice of muzzle device.


  • 5
    Great for suppressed SBR

    Posted by LP on 16th Jun 2020

    Great barrel for suppressor host. Rigidity of this barrel profile helps to minimize point of impact shift with the added muzzle weight of a suppressor.

  • 5
    Perfect for hrt build

    Posted by Matt on 23rd Feb 2020

    This is the perfect profile for an FBI HRT clone. The gas block is pinned in but a vise, punch and hammer take care of them in no time.

  • 5
    Colt M4 commando barrel

    Posted by wayne b on 14th Jan 2020

    Excellent barrel , tested for function , will become part of SBR build.

  • 5
    Colt M4 Commando Barrel

    Posted by David on 11th Dec 2019

    Excellent product with no complaints.

  • 5
    Colt FBI barrel

    Posted by Brian Jaynes on 29th Jul 2019

    Quality Colt item in factory plastic packaging. Happy with purchase

  • 3
    ***BE AWARE***

    Posted by Unknown on 7th Jul 2019

    Great barrel, BUT, be aware these barrels have a .073 diameter gas port. I have 3 examples of this barrel and all three measure the same, .073. Unless pared with an adjustable gas block or gas port restrictor your rifle will be overgassed. For suppressed use it will be severely overgassed. The gas port size should be listed in the product description.

  • 4
    Colt M4 Commando Heavy Contour B.

    Posted by KEN on 2nd Jul 2019

    Item just as described, Factory Colt!! "Recommendations" Please do something in regards to you're shipping/packaging Dept. Otherwise, would be 5 STARS?

  • 5
    Colt M4 Commando 11.5 inch 5.56mm Heavy Barrel

    Posted by Donald Drake on 26th Jun 2019

    This product was new in the bag and exactly what it said it was.

  • 4
    Great Barrel. Need info on specs...

    Posted by Unknown on 18th Jun 2019

    Installed barrel into a Colt upper receiver with Colt BCG. Swapped my Aimpoint from my 6920 and the first shot was in the X at 50 yards! No need to zero! Crazy. 1.5 MOA barrel with surplus ammo. Bought this because the FBI HRT barrels are supposed to have a .069 gas port. No one at AU could confirm this... or tell me anything about the barrel. I question that GP size as xm193 is ejecting at 1:30 and the cases have a ding from the brass deflector. Fiocchi .223 and Brown Bear function fine and eject at 3:30-4 o’clock. Wanted this barrel for 50/50 suppressed use. May get a BRT reduced gas tube for it. AU shipped fast but they should have someone capable of answering technical questions.