Uppers | Upper Receiver Assemblies AR10/AR15 Receiver Groups
Billet uppers are carved from a solid chunk aluminum using a CNC machine. Forged uppers are formed by being hammered and compressed into a die shape that is generally close to that of the finished product. Then the machinist removes small amounts of material with a CNC machine to bring the specifications down to their final size. Metallurgists agree that a forged piece of aluminum is stronger.