AR15 Assembled Upper Receiver - FDE- We've been working with our local Pro Fab manufacturing company to produce the best possible Mil-Spec compatible AR15 Upper and Lower Receivers. These AR15 Uppers are assembled with the port door and forward assist already installed. Forged from 7075-T6 aluminum, they are precision machined to mil-spec M16/M4 specifications and feature M4 feedramps. Match this upper with one of our AR15 lower receivers for a solid and dependable fit. Features: