Years back, a buddy of mine actually had a contest at his yearly bbq for our maintenence crew, who could build the best spud gun. We had about 8 or 9 different ones show up, compressed air, lighter fluid (flame out the barrel) different designs, some with twin burn tubes, etc. When we ran out of spuds, we found corn was a great substitute, being right next to a 300 acre field of it. I'm talking mid summer unripe corn, almost like sweet corn, break the cob in half, it fits the barrel like a bullet, the kernals squish a bit and seal it tight, we were launching some of them almost out of sight with the bigger cannons, started bombarding a small pond past his property, those ducks almost had heart attacks with all the corn barrages !!

 

Now that's a funny picture. We used a tennis ball that we cut grooves in to make it fit. Finally lost it when it got dark.

 

I'm telling ya..... soft field corn or sweet corn works better than wittling down or mashing a potato in there, fits like a bullet, and seals tight, just a wood dowel as a ram rod, and you are set to fire !! mmmmm......corn...... and you can get 2 or 3 "bullets" from each ear, just break it into 3-4" long sections, and it flies !!!

 

I've built several over the years, mostly simple ones, though one was made like a mortar tube, a couple like a bazooka, and several smaller "Trunk of the car" models with threaded barrels to make them easier to transport.

I've always found that Aqua-net hairspray gave me the best results. For some reason, it just seems to have the most flammable cocktail of crap to ignite! Thanks, but Propane and Ether scare the hell outta me!

As for ammo, I use standard potatoes that are "peeled" when entering the barrel.

I use a 16" long, 3" combustion chamber, a reducer to a 30" long 1.5" barrel with the barrel sharpened at the firing end to assist the peeling of the potato on the way down the bore with the assist of a 3/4" dowel rod.

I will say that I've always erred on the side of caution on the ones I've built. I always use a cross-drilled grade 8 bold at the combustion chamber end of the barrel to prevent over-ramming the projectile. The bolt is of course sealed with JB Weld to prevent burn-through, and primed and solvent soaked joints to keep things together.

Spud guns can be lots of fun, but you gotta watch what you point them at: a good friend of mine had his hands full with a civil and criminal complaint because he was an idiot and shot a nice sized hole in a box truck's box! (I'm sure the guy driving it at the time PROBABLY had to change his underwear when that thing went off!!!!)

 

Built a simple one with a grill igniter, but used acetylene as a propellant. Holy sh*t was it loud. We shot it so much it eventually blew up in my buddies hands (thank god no one was hurt).

 

speaking of this I have all the parts in my shed to make a new one and havent finished it up yet I need to get that baby together

 

I've used acetylene in my spud gun once.... just once. literally put me on my ***. acetylene is a bad idea in a spud gun as it actually "detonates" (supersonic) instead of deflagrating (subsonic) like other slower burning gasses (I'm simplifying it greatly). Your pvc spud gun WILL fail if you use acetylene- and you'll be lucky to get out of it with just a few scars...

 

Ya, thats not a gas you want to use. I have had great results from just hair spray or even starting fluid, but that stuff can be a bit "snapy" too.

 

anyone ever do a golf ball cannon?