Colt 11.5 inch Monolithic Upper Receiver Assembly

(17 reviews)
Current Stock:

Colt LE6943 11.5 inch Monolithic Upper Receiver Assembly


The Colt LE6943CK Monolithic Upper Assembly feature's Colt's new monolithic upper receiver. In addition to an uninterrupted full-length front rail, this upper receiver allows for a free-floated barrel. This LE6943CK Monolithic Upper Assembly also features a gas-block mounted front flip-up sight and a flip-up rear sight. The barrel is Colt's standard 11.5" chrome lined M4 barrel with an A2 flash hider up front.

Package Contents

  • Colt LE6943CK Monolithic Complete Upper Assembly
  • Complete M4 Full Auto Bolt Carrier Assembly
  • Charging Handle
  • Backup rear sight
  • Folding Front Sight
  • Manual


  • 11.5-Inch 1/7 twist Mil-Spec chrome lined MP tested barrel
  • Unique direct gas operating system eliminates the conventional operating rod and results in fewer and lighter components
  • Accommodates the full range of 5.56mm ammunition, including the NATO M855/SS109 and U.S. M193, utilizing a rifling twist of 1 turn in 7"
  • Straight-line construction disperses recoil straight back to the shoulder, increasing handling capabilities, especially during repeated fire
  • Cartridge case deflector allows easy operation in both right and left handed shooting positions for increased tactical applications
  • Muzzle compensator further reduces muzzle climb and helps eliminate flash and dust signatures
  • Ejection port cover protects the chamber from dust and mud
  • Field strips easily without special tools for simple field user maintenance
  • Flat top receiver allows for removable carrying handle and easy mounting of accessories
  • Target style rear sight features dual apertures (0-200m, 300-600m) and adjusts for both windage and elevation
  • High strength materials for greater comfort and effectiveness
  • Caliber - 5.56mm
  • Gas Direct system, Locking bolt
  • Front Sight - Adjustable front
  • Rear Sight - Target sight adjustable for windage and elevation
  • Flash Hider


  • 4
    Fast shipping but item was a bit scratched.

    Posted by Unknown on 7th Jan 2021

    The item came quickly as expected but there were two scratches on the rails that are definitely not supposed to be there. Ordered some touch up paint but was a bit disappointed since the item was new.

  • 5
    Colt 11.5" Upper Receiver Assembly

    Posted by on 15th Dec 2020

    The product shipped fast. Unfortunately the box was severely damaged when I received it. Overall another flawless transaction with Arms Unlimited. I recommend them and will buy from them again.

  • 5
    Colt Upper

    Posted by Range Warden on 2nd Nov 2020 service was great. The Colt upper came in a Colt box with the upper in the factory sealed bag. It also has the nicer rear sight, not the MagPul sight. I have ordered guns, and hard to find parts from them in the past and have always been pleased.

  • 5
    Colt 6943 Monolithic Upper

    Posted by Lane F on 28th Oct 2020

    Genuine Colt 6943 Upper New in Colt Box, good price in these days of shortage, fast shipping....Arms Unlimited is one of my favorite dealers

  • 5
    There is a QD Sling Swivel Hidden in the Box!

    Posted by PT on 23rd Sep 2020

    It's a brand spanking new monolithic with Colt "C" and Brass Aluminum Forging Enterprises forge marks (Square). Fastest shipping in the business and came in a Colt box (for some that seems to matter). Colt charging handle and BCG are included along with Magpul rear BUIS. I threw that away and put on a MaTech with a Forward Control Designs Retrofit Kit. Be careful and do not throw away the box too quickly! There's a QD sling swivel hiding in there! There are a lot of 11.5's from different manufacturers for sale out there, which obviously are not it was a no brainer for me.

  • 5
    Colt Monolithic upper Great product

    Posted by Michael H on 25th Aug 2020

    Very well built, happy with sight in. 1 moa, I was a little disappointed when I didn't get the rear sight as advertised. It came with a Magpul rear sight.

  • 5
    Colt Upper

    Posted by Michael Wixom on 27th Jun 2019

    Market Price, item arrived as expected. Arrived in a Colt Rifle box that had the label removed. BCG was complete and both sets of BIS were present. No documentation. Fast Shipping good comms.

  • 5

    Posted by M. W. on 26th Feb 2019

    I've made multiple purchases through AU. Every time the experience is professional and easy. Purchases made and sebt through my local FFL were easy, and purchases sent to my home arrived quickly. Never an issue ever. Will continue doing business in the future, and always recommend highly.

  • 5
    Great Service!!!

    Posted by A Satisfied Customer on 21st Aug 2018

    Great folks to do business with. Super fast shipping, best prices around. Flawless transaction all the way around. They even accommodated specialized shipping request. I will definitely do business with them again.