I thought, as a first gun (and probably last...), I should make something simple, but original; a pill bottle, but smaller and easier to disguise. What I have done is do away with the pill bottle itself, block one end of a pen tube (the thin end) with some wax and stick the electrodes straight above the blockage. Then rig it up to a Piezo-Electric generator (The thingies that you get from electric lighters). Simple, right?
Picture of whole thing.
Ignitor.
Sorry about fuzzy pictures, I don't have a very good camera. I might get a video of it working when I get some fuel and bbs for it (It will only work with fluid, it dosen't have the capacity to take gasses and aerosols, and I need some bbs with it as well, i'll get round to it and update this as and when I get them, but it'll go untested for now. I might even put up a video on youtube on how to make one, but it's pretty simple to understand )
A pill bottle, but without the pill bottle!
I thought about using the tube that comes with the long lighters as the barrel and just leaving the lighter mostly intact.
"There isn't a problem in the world that can't be solved by the proper application of explosives"