Colt AR15A4 5.56mm Semi-Auto Lower Receiver Assembly

(11 reviews)
Current Stock:

ALL Semi-Auto Colt Rifle Receivers will be marked "Carbine" as of Q4 2020

Factory Colt complete lower receiver assembly to build your AR15, M16 or MK12. Compatible with all mil-spec AR15/M4/M16 upper receivers. Manufactured to truly meet and exceed all Mil Spec standards.

This item is a serialized part, considered a firearm and requires transfer through a FFL


  • 4

    Posted by Thomas Lanctot on 17th Jul 2022

    My only improvement would better and faster phone and computer communications.

  • 4
    Happy to complete my war pony COLT AR-15 A 4

    Posted by DAVE on 2nd Apr 2020

    Nice complete A 4 lower price was ok this completed my A 4 something about the white label lowers . I have bought 2 and both out of box THE SELECTOR didn't work . I couldn't get the selector to turn from safe to fire so i ended up replacing the brass detent the tip on the replacement was smooth and well machined and the one out of the lower had burrs and uneven finish. Anyway that's a big thing to miss COLT QA. ? do better.

  • 5
    Colt Defense A-4 Lower

    Posted by Roger Herron on 23rd Mar 2020

    Product NIB, as described, at a reasonable price point.

  • 5
    colt lower

    Posted by john on 3rd Jun 2019

    Easy transaction, good communication on shipping.

  • 5
    A15-A4 Riffle Lower Reciever Assembly

    Posted by David on 22nd May 2019

    Hard to find Colt part...perfect condition... have used before and will use again. Thanks

  • 5
    Fast shipping on a quality lower receiver

    Posted by Ben on 28th Feb 2019

    I was notified by email that this product was back in stock and purchased one. Good thing too because it was out of stock the next time I checked on it. They shipped my lower the same day that they received the FFL from my dealer. It was a great transaction. Thanks for everything.

  • 5
    Great lower

    Posted by Zack on 25th Feb 2019

    Item as described and in perfect condition. Excellent lower for my mk12 build. The only knock is that it took 10 days to ship but other than that it was a perfect transaction. Will buy from again.

  • 5
    Colt AR15-A4 Rifle Lower Receiver Assembly

    Posted by Chris K. on 24th Nov 2018

    Good price. Fast shipping. Item in perfect condition.

  • 5
    Hassle-Free Service

    Posted by C. Larsen on 26th Sep 2018

    I was a bit concerned that AU might have a problem working with my local FFL dealer - but nope. No problems whatsoever. That was very welcomed. Plus, the product is exactly as advertised. The entire affair was hassle-free, and I appreciate that service.