Rock River Arms Completed Upper Receiver National Match A4 .223/5.56mm 20 Inch Barrel 1-8 Twist 1/2-28 Thread Free-Float Handguard w/Post Black

Rock River Arms

Overview

The Rock River Arms Completed Upper Receiver National Match A4 is a fully assembled unit designed for the AR-15 platform, featuring a 20-inch barrel with a 1:8 twist rate. This twist rate is optimal for stabilizing a variety of bullet weights, making it versatile for different shooting applications. The 1/2x28 thread pitch allows for easy attachment of muzzle devices, enhancing customization potential for your build. This upper receiver is commonly found in builds chambered for 5.56 NATO, making it a reliable choice for precision shooting and general use.