Pretty good idea randomvictim, but I think it would make a huge mess trying to cram a spitball down there, I think I would put the TP in first and then pour some water on it. I may actually try that.
I'm not sure if I want to reveal what my main project is. I do like to surprise people, but I will say that it has to do with high efficency, and it does look promising.
mark, actually I use mostly PVC fitting, its just that they are almost all heavily modified. On the small guns I use PVC stock, but on the bigger ones I mostly just mix, match, and modify PVC fittings to do what I want. In fact, no PVC stock was used on this gun.
Heh, yeah I just leave my cannons laying around in the garage and in my room, but usually when anyone that would be remotely intrested in these things comes to my house my parents have already told them that I build cannons, so I just pick out a few to show them when they ask about it. My dad said that the guy who came to repair our water softener was into spudguns and he spent most of the time looking at my stuff and telling my dad about his guns. Unfortunately I wasn't there at the time.
Thanks for all the compliments.