Rock River Arms Completed Pistol Upper Receiver A4 .223/5.56mm 16 Inch Barrel Mid-Length Profile 1-9 Twist 1/2-28 Thread A2 Flash Hider w/Gas Block
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Rock River Arms
Overview
The Rock River Arms Completed Pistol Upper Receiver A4 features a complete assembly designed for AR-15 platforms, equipped with a 16-inch barrel that offers a mid-length gas system for smoother cycling and reduced recoil. It is chambered in 5.56 NATO and has a 1:9 twist rate, making it versatile for stabilizing a variety of bullet weights. This upper receiver is commonly used in lightweight builds where maneuverability and handling are prioritized.
Specifications
Rock River Arms Completed Pistol Upper Receiver A4 .223/5.56mm 16 Inch Barrel Mid-Length Profile 1-9 Twist 1/2-28 Thread A2 Flash Hider w/Gas Block
Price and stock
The Rock River Arms Completed Pistol Upper Receiver A4 .223/5.56mm 16 Inch Barrel Mid-Length Profile 1-9 Twist 1/2-28 Thread A2 Flash Hider w/Gas Block was out of stock everywhere we track for all of August 2026, and today the one retailer we track is out of stock. Listed prices start at $488.49 at Optics Planet for when it comes back.
Prices checked · refreshed daily across 35 retailers
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