Due to the overwhelming positive response I got for my portal gun, I'm really going to try to get the write-up done ASAP, which is easier said than done because I haven't started it yet!
But I have LOADS of WIP photos and measurements so I'll try to be as in-depth as possible so that you might have an easier time with building your own gun if you decide to make one of your own 
Let me know in the comments if you have a specific topic/question you want me to cover and I'll do my best to make it clear
P.S. I've been featured on BuzzFeed's front page, which is amazing! www.buzzfeed.com/tardistrekkie… (But they changed the title of my post and now I can't fix it! I hope NECA doesn't come after me!)
