Rock River Arms Completed Upper Receiver A4 .223/5.56mm 10.5 Inch Barrel 1-7 Twist 1/2-28 Thread R4 Handguard A2 Flash Hide Black

Rock River Arms

Overview

The Rock River Arms Completed Upper Receiver features a 10.5-inch barrel chambered for 5.56 NATO, offering a compact option for your AR-15 builds. With a 1:7 twist rate, this upper is designed to stabilize a wide range of bullet weights, making it versatile for various shooting applications. The A4 receiver type and 1/2x28 thread pitch ensure compatibility with standard AR-15 components, while the sleek black finish gives it a tactical appearance. This upper is commonly found in short-barreled rifle configurations and builds focused on maneuverability and close-quarters engagements.