A good spud gun can hurl it at up to 400 miles (643 km) an hour.

It can fire potatoes (spuds) and tennis balls, as well as other common objects.

STC's owner, by the name of Joel Suprise, says that anything is a worthy projectile as long as it fits the barrel size.

It's called "pneumatic."

They're usually made out of PVC piping, although some are made of acrylonitrile butadiene styrene (ABS) or aluminum.

Spud guns usually have three main components, two of which are a barrel and a chamber. The third is a firing mechanism.

The sharpened part, like a barrel knife, shaves off any excess potato while you load it.

Upon ignition, there is an explosion which creates hot gas under pressure. This forces the projectile out through the barrel.

The pneumatic spud gun uses compressed air to generate high pressure.

Breech loading means loading the potato inside through an opening near the chamber (unlike the usual method of forcing the potato down the barrel using a rod).

The spud gun has two metal points inside the chamber, which function like a spark plug in a car to cause ignition.

They use propane from a standard tank in order to inject a precise amount of fuel into the chamber.

Some spud guns are designed with dual ignition, essentially creating more "bang" for the same price.

A pneumatic spud gun usually has a larger chamber than a combustive one.

A special valve keeps the air inside, until someone opens it. Then air rushes in with a bang and the potato is forced out.

A rifled barrel seems to work. It gives a spin to the projectile, stabilizing it and hurling it further and with greater accuracy.

A specially-designed tornado simulator was made for the Department of Agriculture. This was done in order to lead to better building techniques.

Pumpkin is the projectile-du-jour at the Punkin Chunkin championship.

Gasoline and oxygen are pretty dangerous in a spud gun. They're too flammable.

It classifies spud guns not as firearms, assuming they're used recreationally. This notwithstanding, in most U.S. cities, it is illegal to fire a spud gun.