Here's my attempt at the MG6 Magnum Pistol from Halo. Just use the exploded image for assembly, you may need to sand the connection points so they fit. Here's the assembly and painting instructions https://www.youtube.com/watch?v=M-GsUA9xisU

Be sure to post a make and check out my other models. 

If you like my work and would like to support it and future projects, you can buy me a Ko-Fi(though I am more of a tea person), https://ko-fi.com/reprops