Specna Arms Upper Receiver for CORE M4 – Polymer Black

The Specna Arms upper receiver for CORE M4/AR-15 is a precision-engineered replacement component designed to streamline your M4 platform AEG build or refresh. Whether you’re upgrading an existing CORE gearbox setup or assembling a custom rifle, this upper receiver delivers reliable performance with practical modularity at its core.

Key Features

• Polymer construction with steel trim parts – balance of durability and weight
• 20mm RIS / RAS rail system – mounting flexibility for optics, grips, and tactical gear
• CORE™ M4/AR-15 compatibility – direct fit for Specna Arms CORE gearbox systems
• Black finish – professional appearance, low-glint aesthetic
• Ready-to-assemble component – integrate into builds or replacement projects

Real-World Use Cases

Ideal for skirmishers looking to repair or customise an existing CORE M4, milsim players building a modular platform rifle, or upgrades seeking drop-in compatibility with Specna Arms’ proven gearbox architecture. The 20mm RIS rail gives you genuine flexibility for sight mounts, foregrips, and other 20mm accessories without compromise.

Technical Specifications

• Brand: Specna Arms
• Type: Upper Receiver Assembly
• Platform: M4/AR-15 (CORE™ compatible)
• Construction: Polymer with steel trim
• Rail System: 20mm RIS / RAS
• Colour: Black
• SKU: SPE-09-027528-00

Compatibility & Upgrades

This upper receiver is engineered for Specna Arms CORE™ gearbox systems. It accepts standard M4 inner barrels, hop-up units, and trigger assemblies within the CORE specification. The 20mm rail accepts any standard military-specification rail-mounted accessory – scopes, red dots, laser units, vertical grips, and hand guards all integrate seamlessly.

UK Legal & Site Notes

As a component part, this upper receiver is subject to UK airsoft regulations. Check your skirmish site or milsim event rules regarding maximum velocity, firing modes, and magazine capacity for the complete rifle. Specna Arms products are widely accepted across UK sites.

Ready to complete or restore your CORE M4? Order the Specna Arms upper receiver from Airsoftdirect today and enjoy fast UK delivery and expert support.