Swipe or use the left and right arrow keys to browse photos. The thumbnails below also respond to the arrow keys. Select a photo to view it full screen.
Heckler & Koch MR556A4 URK Upper Receiver Assembly
Shipping and tax calculated at checkout.
Ships to your address
Delivery options and cost are shown at checkout.
Description
The Heckler & Koch MR556A4 URK is a precision-engineered complete upper receiver chambered in 223 Remington/5.56 NATO, designed for seamless integration with standard AR-15 lower receivers.
This 16.5-inch barrel features a 1-in-7 twist rate and suppressor-ready 1/2X28 threading with an adjustable gas regulator for fine-tuned cycling performance. The M-LOK handguard provides a lightweight, modular platform for accessory attachment.
Factory-equipped with the bolt carrier group, charging handle, buffer weight, and buffer spring, this complete upper ships ready for installation on your AR-15 lower receiver.
- Chambered in 223 Remington/5.56 NATO
- 16.5-inch barrel with 1-in-7 twist rate
- Suppressor-ready 1/2X28 threaded barrel with adjustable gas regulator
- M-LOK handguard for accessory modularity
- Matte black anodized finish
- Includes bolt carrier group, charging handle, buffer weight, and buffer spring
Specifications
- Model
- MR556A4 URK
- UPC
- 642230270213
- MPN
- 51000384
