Hokai... so here's the thread, it's chilling... dang that is a sweet thread you might say! Round? No. So ruling out the logos melting, spammers becoming crashing into us, the moderators leaving, and the server exploding, we are definitely going to spam ourselves to death. For those End Of The World fans^^ Hokai, so I've built a spudgun. Most people don't realize just how easy it is, and how cheap it is to build one. These things absolutely rock, and will put holes in walls. So if you wanna blow the crap out of someone's mailbox... it's not my responsibility. I used 3 inch ABS pipe for the combustion chamber (ABS is the black plastic pipe, and PVC is white.) and 2 inch ABS for the barrel. The combustion chamber is 2 feet long, and the barrel 4 feet long. They are joined by a 3 to 2 inch reducer. The other end of the combustion chamber has a female adapter, with a sewer end plug screwed into it. I used a barbecue igniter to make the spark, so I made two small holes in the sides at the middle of the combustion chamber. I made a wire from aluminum foil and attached it to one wire, so the other end is about 7 mm from the other wire, thus allowing a spark. I beveled the front of the barrel so when you push a potato against it, it'll core it nicely, and the excess will fall off. I also made a hole in the side of the barrel by the reducer and put a nail in it so that when the potato is pushed down by a ramrod (wood dowel or broom handle), it won't fall into the chamber. I use hairspray as the propellant. Works every time! I've estimated my highest launch to be in excess of 400 feet.