Potomac Armory Mk18 Mod 0 5.56 NATO Upper Receiver Group - "Near Clone"

This is a CQBR style upper using a Troy quad rail

The Foundation of Solid Clone Rifle: Potomac Armory's Expert Craftsmanship

In the world of firearm upgrades, the Potomac Armory Mk18 Mod 0 5.56 NATO Upper Receiver Group CQBR offers unparalleled quality and performance. Exclusively assembled by Potomac Armory for Charlie's Custom Clones, it's the epitome of precision engineering. Fusing Mil-Spec perfection with affordability, this upper receiver group boasts a Troy M4 RAS. The rich legacy of Troy, an old school manufacturer respected for solid AR15 parts, finds its expression in this fine piece of craftsmanship.

Based upon US Navy SEAL Heritage in GWOT

The roots of this Upper Receiver Group can be traced back to the original Mk18 Mod 0, meticulously designed by the US Navy for the SEALS. This compact iteration of the 14-1/2" M4A1 was the weapon of choice for covert operations.  The upper receiver was known as the Close Quarter Battle Receiver, CQBR.  Eventually, full Mk18 rifle kits were outfitted by Crane, and the Mod 0 with the A-frame front sight post was issued to Navy SEALS and US Marines.  The Army continued to refer to their short barreled rifles as the M4A1 Block 1 CQBR.

Superior Performance and Value: Unbeatable Features & Specifications

This product encapsulates a multitude of standout features. A Mil-Spec M4 upper receiver, constructed from 7075 military aircraft-grade aluminum, ensures long-lasting durability. A chrome-lined and phosphated bolt carrier group adds to the reliability, especially during rapid fire or suppressed shooting scenarios. The inclusion of a PRI Gas Buster charging handle designed specifically for the MK18 safeguards against excess gas blow-back, a common issue with short-barreled upper receivers. Finally, the Colt 10.3” Crane chrome-line Mil-Spec barrel and Mil-Spec A2 flash hider are carefully tailored for optimum performance.

Features and Specifications

• Mil-Spec M4 upper receiver, Mil-Spec perfection. 7075 military aircraft grade aluminum with hardcoat anodizing, M4 feedramps, and engraved T-marks with Potomac Armory CAGE Code and interior dry film lubricant (DFL).

• TROY M4 RAS quad rail with 2 mil-spec ribbed rail guards.*

• Mil-Spec chrome-lined and phosphated bolt carrier croup, Mil-Spec phosphated finish. Note: For effective, reliable shooting with a 10.3" barrel, you need a high quality bolt and carrier group, especially if you might be shooting rapid fire or suppressed. We have hand-picked our BCG from a Tier-1 supplier with tool steel phosphated carrier, staked gas key, and Carpenter 158 steel bolt, MPI inspected.

• PRI Gas Buster charging handle 
  

• Colt 10.3” Crane chrome-line Mil-Spec barrel with 0.070” gas port and carbine length gas system with integrated FSB. We have taken a factory 14.5" barrel and cut it down to 10.3", exactly as the first Mk18 barrels were done by the Navy armorers at Naval Surface Warfare Center Crane in Indiana. We have sent these barrels to one of the best barrel shops in the US, with a long history of providing military and precision shooting barrels, and had the barrels re-crowned, threaded, and the gas ports opened to 0.070". The enlarged gas port was a later improvement, much after the first Mk18's were cut in 2001.

• Colt A-Frame "F" height front sight base, factory installed by Colt.

• Mil-Spec A2 flash hider, which can be easily swapped out for other flash hiders, especially for use with suppressors.

• Magpul MBUS Gen2 rear back-up sight. You may upgrade to a different rear BUIS, if desired. Just ask the Charlie's team. We found that people are either very picky about rear sights, like a KAC or Matech, or will want a great optic, like an Aimpoint or EOTech, and seldom notice their rear back-up sight.

FAQs

QUESTION:  What is the difference between a Mk18 and a CQBR?

ANSWER:  The upper receiver group of a Mk18 is referred to as the CQBR.  The Mk18 is the entire weapons system, and is a vernacular used by the US Navy.  The saying goes that "blue and green don't mix well," which refers to internal stubbornness between the US Army and the US Navy.  LOL.  The Army operators continued to refer to their short barreled battle rifles with a fixed front sight post as a Block 1 CQBR, while the SEALS and Marines would refer to that as their Mk18 Mod 0.

QUESTION:  What is a clone and a near-clone?

ANSWER:  A clone rifle is a replica, generally using exact, or as close to exact parts used by military forces in their rifles.  A clone is not fake.  Nothing is further from the truth, as a "clone correct" rifle is an exact replica, as far as law allows.  For example, a clone M16 rifle would not be fully automatic.  A "near clone" is a term that Charlie's Custom Clones uses to present "almost clone correct" or "clone inspired" rifles and upper and lower receivers that balance budget with authenticity.  Charlie's is the largest military clone rifle shop in the US, and while a good many people want near perfect in their clone builds, others do not have that budget, and buying a near clone is a great way to get started in the clone rifle game.

QUESTION:  Can this upper support a suppressor?

ANSWER:  Absolutely.  Charlie's has equipped this upper receiver group with a Tier-1 BCG and the PRI Gas Buster charging handle and the correct gas port size of 0.70" which will perfectly support a suppressor with the removal of the A2 birdcage flash hider, and the installation of a muzzle device to support your suppresor of choice, or via direct thread attachment.

To complete your CQBR or Mk18, Charlie's Custom Clones actually features Mk18 Mod 0 lowers, and the mil-spec vertical grip as well.

Made in the USA

*  Photos show Knights Armament rail covers, but product was changed after pictures to identical rail covers from PAT, the military grade parent of P&S Products.  PAT provides exactly the same rail cover, but is in production in 2023 and comes at much lower unit cost.  If you wish to upgrade, you can add Knights 11-rib rail covers.

All NFA laws apply. If you are uncertain if you can own this, check the federal National Firearms Act, also with your state authorities. I am not your lawyer. You need to make sure you can own it.