6 Best MK18 Upper Clone

Whether you want to build a MK18 MOD 0, MK18 MOD 1 or MK18 MOD 3 URGI. Here are 6 best MK18 upper clone that I found to be the top tier products after using some of them and also basedd on product demo presented from others in the gun communities over the years.

They can go on all AR15 pistol lower receiver builds or NFA registered short barrel rifle lower as long as the overall length is in compliance with laws. 

NFA Disclaimer:

• Assembling this part into a complete firearm makes it a regulated item under the National Firearms Act (NFA).
• Check local and state municipalities for further regulatory requirements.
• Buyer is responsible for complying with all NFA rules and applicable laws.

Finish your build with our AR15 lower parts kit guide here

Customize MK18 upper with specific parts here

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Top MK18 Upper Clones

Daniel Defense MK18 Compete Upper - Best For MK18 MOD 1 Build

The Daniel Defense brand MK18 compete upper is the most original upper receiver used by USSOCOM.

Key Features:

• RIS II rail with Bolt-Up System rigorously tested by USSOCOM
• 10.3-inch Cold Hammer Forged barrel ideal for CQB operations
• Independently ambi GRIP-N-RIP Charging Handle for left- and right-handed shooters
• M16 profile bolt carrier group standard in all Daniel Defense complete upper receiver groups

Geissele MK18 MOD 3 10.5" URGI Upper - Best MK18 MOD 3 Build

Geissele CQBR URGi Upper Receiver Group, the updated 2019 US Military version for close quarter battles. This is known as the CQBR-URGi, and it features the signature Geissele MK16 rail. 

The upper is specifically designed to withstand the demands of the new M855A1 (AB57) ammunition, the USASOC URGI maximizes its capabilities. 

For the money, you are getting everything in this complete upper without having to buy additional upgrades.

• Geissele Super Modular Rail MK 16 handguard: This allows for improved handling and comes with an MLOK handguard, making it much slimmer than the RIS II quad rail.
• Hammer forged barrel: This provides increased durability and accuracy, ensuring a reliable and precise shooting experience.
• Carbine gas system: This system optimizes performance, making the weapon more efficient and reliable.
• Compatibility with M855A1 (AB57) ammunition: This enables the full utilization of the ammunition's capabilities, enhancing overall performance.
• Easy integration: The USASOC URGI can be seamlessly integrated with existing AR15 lower builds, making it a versatile addition to your arsenal.
• Close resemblance to USASOC equipment: This upgrade closely resembles the upper receiver group currently used by USASOC, ensuring authenticity and quality.

PSA 10.5" 5.56 NATO Upper - Best For MOD 0 Build

The PSA 10.5" 5.56 NATO classic upper features the old school polymer two piece handguard for anyone interested in building a reliable MK18 MOD 0 clone. This lower than $200 bare bone 10.5" upper receiver also serves as a baseline configuration for users to add desired accessories.

The Phosphate treated Upper is an excellent choice for several reasons:

• Trusted in house manufacturing: Palmetto State Armory is renowned for producing mil-spec and affordable AR-15s and AR parts without any middleman, which means huge savings for the buyers.
• F-Marked front sight post: This is correct for the MK18 Mod 0, ensuring authenticity.
• 10.5-inch barrel: This is the appropriate length for the Mod 0, and the barrel is made of high-quality Chrome Moly Vanadium steel, featuring a 1:7 twist rate and an extremely durable Phosphate coating.
• Carbine-length gas system: This enhances the weapon's performance and reliability.
• A2 flash hider and classic military-styled handguards: These add to the authentic appearance of the MK18 Mod 0 clone.

PSA 10.5" 5.56 NATO MOE Upper

The PSA 10.5" 5.56 NATO is the same as the one recommended above, and this one features the classic MOE handguard if you need accessory mounting capabilities without needing a $300 - $400 aluminum handguard.

This upper features the same components.

PSA 10.5" M LOK Upper

The PSA 10.5" M LOK upper features the same core firearm components as the 5.56 NATO MOE and classic upper receivers.

If you're open to a slightly less original MK18, but still features a good handguard. The the PSA 10.5″ Upper with an M LOK rail and a flash can offer a fantastic quality at an affordable price. 

Magpul MBUS backup sights: These sights are included with the upper, adding value and functionality.

M16 Profile bolt carrier group: Complete upper ready to use

Aero Precision M4E1 10.5"

Aero Precision is another favorite manufacturer for AR-15s and AR parts, known for their high-quality products at reasonable prices. The M4E1 10.5″ Complete Upper Receiver with the Atlas S-One Handguard is an excellent MK18 upper clone

• High-quality 10.5-inch barrel: Made from Chrome Moly Vanadium steel and featuring a 1:7 twist rate, this barrel ensures 5.56 NATO accuracy and durability.
• Unique upper receiver design: The Aero Precision upper receiver has a distinctive 'billet look' even though it's forged, making it stronger and more lightweight.
• 9-inch ATLAS S-One handguard: This innovative handguard features unique aesthetics, and it also improves ergonomics and comfort by removing some of the Picatinny railing at the top. 
• Versatile railing options: The handguard still offers railing on top for backup iron sights and features MLOK compatibility, allowing you to place MLOK rails for accessories in the 3, 6, and 9 o'clock positions.