Well, I spent most of the day checking out local stores looking for supplies, and the largest size PVC pipe I can find is 2". I have to check Grover's tomorrow on the hope they have larger, but other than that I am looking to be S.O.L. on parts. Any ideas on that one?

Thanks, and I was planning on combustion, seems to be the simplest for beginners.

I am new to the realm of Spudguns/cannons. I would like to make one in the very very near future, but would like tips and advice on an easy build for my first time, fairly inexpensive preffered. I have a general understanding on how it works, but would like some more input. Any tips?