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 Black

Rock River Arms

Overview

The Rock River Arms Completed Pistol Upper Receiver A4 features a 16-inch barrel optimized for the 5.56 NATO caliber, making it a solid choice for precision shooting and reliable performance. With a mid-length gas system, this upper provides a smoother cycling action, which can enhance accuracy and reduce recoil. The 1:9 twist rate allows for effective stabilization of a range of bullet weights, making it versatile for various ammunition types. This upper receiver is commonly found in builds aimed at tactical use or recreational shooting, where reliability and ease of handling are key.