Rock River Arms Completed Upper Receiver R3 .223/5.56mm 18 Inch Barrel Mid-Length Plofile 1-8 Twist 1/2-28 Thread M-LOK Handguard Brake Black
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Rock River Arms
Overview
The Rock River Arms Completed Upper Receiver R3 is a fully assembled upper designed for the AR-15 platform, featuring an 18-inch barrel optimized for 5.56 NATO ammunition. With a mid-length gas system, this upper enhances reliability and reduces recoil, while the 1:8 twist rate provides versatility in stabilizing a wide range of bullet weights. This configuration is often used in builds aimed at precision shooting and versatility, making it a solid choice for both competitive and recreational use.
Specifications
Rock River Arms Completed Upper Receiver R3 .223/5.56mm 18 Inch Barrel Mid-Length Plofile 1-8 Twist 1/2-28 Thread M-LOK Handguard Brake Black
Build history on GunPartPicker
Builders on GunPartPicker first added the Rock River Arms Completed Upper Receiver R3 .223/5.56mm 18 Inch Barrel Mid-Length Plofile 1-8 Twist 1/2-28 Thread M-LOK Handguard Brake Black to a build in June 2026.
Today none of the 2 retailers we track has it in stock right now. Listed prices start at $615.85 at BattleHawk Armory for when it comes back.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 37 retailers
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