Mk18 Upper Receiver Group Geissele - Colt M4 CQB URGi CLONE CORRECT

Assembled to Order, Ships in 1 to 2 weeks


Geissele / Colt M4 CQB Mk18 Upper Receiver Group (URGi)

Clone Correct version

What if you took a look around and Geissele made a smaller brother to the M4 URGi, and what if it happened to be 10.3" and someone called it a Mk18 Mod X.  We don't know either. 

This model is the Geissele clone correct upper, in a shorter close-quarter battle rifle (CQB) configuration.  Charlie's has worked closely with Geissele to bring you what you are looking for.  

Your choice of the Surefire 4-prong flash hider, or other great Surefire, Colt, BE Meyers and KAC flash hilders.

Each URGI is fitted with the handguard Geissele designed specifically for USASOC, the MK 16 M-LOK™ Super Modular Rail handguard with a full-length Picatinny top rail and lotsa slots for other accessories. T-markings are engraved on the rail but not painted white to help keep the rifle unobtrusive.

Note:  This is 100% Geissele and Colt.  Geissele has assembled the barrel and pinned a Geissele low profile gas block.  4-prong Surefire flash hiders have been timed and installed by Geissele.  The 3-prong flash hiders have been installed and the barrel assembly and Geissele rail has been assembled by Potomac Armory for Charlie's to bring you the clone correct version of this URG.


  • Colt M4 receiver with forward assist, shell deflector & ejection port cover, with Colt "CAGE Code" stamped on left side
  • Geissele 9.3" Mk16 Super Modular Handguard with Geissele roll-marks
  • Daniel Defense 10.3" CHF barrel with 1-7" rifling & 1/2"-28 tpi muzzle threads and carbine length gas system
  • Geissele Airborne (military version with roll-marks) DDC charging handle
  • Geissele Super Gas Block, black nitrided and pinned
  • Colt  M16 bolt and carrier group, with Colt bolt marked "MPC"
  • Surefire SOCOM 4-prong flash hider or the Surefire SOCOM 3-prong WarComp (un-pinned) or other popular flash hiders

Note:  if you select WarComp, we time this as neutral (ports pointed up).  If you want it timed to the starboard side, please make sure to put that in the comments.  Both are correct.  Our gunsmiths prefer ports timed up.


NFA warning:  The Stripped URGI upper receiver group without the pinned flash hider does not meet the 16" minimum barrel length requirement, and requires registration and a tax stamp with the Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE) when assembled into a complete rifle.  Please make sure you fully understand NFA and local laws.

ITAR warning Charlie's Custom Clones ITAR warning:  This item may only be purchased and shipped to US Persons within the USA.  This is a military item, which is restricted from export without US Government permission.

Pictures courtesy of Geissele Automatics, Potomac Armory and Southern Cross, LLC