Anatomy of a Spud Gun: Pneumatic

A pneumatic spud gun uses the same principles of force as a combustive gun. However, instead of using an explosion to generate force, it uses compressed air.

A pneumatic spud gun generally has a larger chamber than a combustive model. The user fills the chamber with air from a pump, an air compressor or a CO2 tank. "With a pneumatic launcher, you have a large volume of relatively high pressure, say 80-100 PSI, that is being dumped instantly…so a good rule of thumb is that a pneumatic launcher will be more powerful than a combustion-based launcher," says Suprise.

Photo courtesy The Spudgun Technology Center A pneumatic spud gun

A valve, typically a sprinkler, ball or piston valve, lies between the pneumatic gun's chamber and the barrel. This valve keeps all the air inside the chamber while the pressure builds. The operator uses a gauge to keep an eye on the pressure. When it reaches a suitable level, the operator disconnects the tank and presses the button or pulls the lever that opens the valve. The air rushes into the barrel, forcing the potato out.

Spud Gun Modifications: Rifled Barrels A potato isn't really an effective projectile. Even after passing over the barrel knife, its irregular shape causes it to fly erratically. Rifled barrels -- like those used in firearms -- make potatoes fly more efficiently. "By putting spin on it, that projectile will stabilize itself and thus give you greater distance and greater accuracy," says Suprise.

Next we'll look at some other ways that spud guns can be used -- aside from firing spuds.