The Colt LE6921CK Upper Receiver Assembly feature's Colt's upper receiver. This LE6921CK Upper Assembly also features a gas-block mounted fixed front sight post with bayonet lug and a flip-up backup rear sight. The barrel is Colt's standard 14.5" chrome lined M4 barrel with an A2 flash hider up front.

Specifications:

14.5 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

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

Link to parts manufacturer