I originally built this rifle for a costume because I wanted something that would look nicely detailed compared to the relative simplicity of the suit. Originally it was just a silver nerf recon but over time I started to customize it as the suit was upgraded and made more complicated. I decided to keep all the functionality of the nerf gun to give me something to show off. (cocking, loading, etc) This project has been on and off for about 2 years now. I occasionally touched it up here and there and added some more detailing.
Some details on how he built it – HERE
I really like the demonstration video too. Nice touch with the HALO style heads up display and music.