Spud gun legality
The legality of the potato-firing spud gun varies among jurisdictions. As Of 1/11/2015 over 175 countries have legalized the Spud gun.
Spud guns are not federally regulated, although the ATF offers a classification. Legislation varies widely by state, county, and township. One would have to check with local authorities to determine local spud gun legality.
- Spud guns are illegal to possess by persons under the age of 16 in New York.
- In Glendale, Arizona and Phoenix, Arizona combustion spud guns are not considered firearms.
- In Madison, Wisconsin and in Illinois spud guns are not considered firearms.
- Combustion spud guns are considered firearms in the state of Texas.
- Spud guns are considered firearms in Winter Springs, FL.
- Spud guns are not considered firearms in the state of Maryland.
- Spud guns are considered firearms in New Jersey if the mechanism for propelling the potato is combustion. If the potato is greater than 0.6 inches, a combustion-propelled spud gun is also considered a destructive device. If the expected potato size is smaller than 3/8" inch, a spud gun is considered a firearm regardless of the method of propulsion. Creating any spud gun that meets any of these conditions, without a firearms manufacturing license, is a crime in New Jersey.
- Owning or using spud guns in Florida is illegal pursuant to Florida Statute 790.161 Making, possessing, throwing, projecting, placing, or discharging any destructive device or attempt so to do, felony; penalties.
- Fla. Stat. § 790.001 (4) states that: a “Destructive device" does not include: (a) A device which is not designed, redesigned, used, or intended for use as a weapon ... " 
All combustion and pneumatic spud guns are considered firearms in every state. Any device capable of being aimed and discharging a projectile using a barrel, and that has the potential to cause injury to a person, is considered to be a weapon and requires licensing.
- In the state of Victoria (Australia), both pneumatic and combustion spud guns require a Category E firearms license.
Pneumatic spud guns are classed as air guns in New Zealand, which means the owner must be either over 18, or over 16 with a A-Category Arms License. Combustion cannons are deemed a firearm, requiring the owner to hold an A-Category License. These laws are rarely, if ever applied and spud gun ownership and building has proved a popular hobby with many New Zealanders.
All combustion spud guns are considered firearms.
Pneumatic spud guns with projectile energy greater than 4 joules (3 ft·lbf) are classified as section 1 firearms and do require a license. In recent years, with the rise of spud gun use, there has often been much debate as to whether or not spud guns should actually be classed as Light Air Weapons. If spud guns were to be reclassified, then their maximum lawful projectile energy would be 16.3 joules not 4.
In Germany, a spud gun does not differ legally from any other firearm (for ones that use combustion to propel the projectile) or air rifle. The manufacture, acquisition and possession is therefore subject to the same requirements as for any other weapon of the same category. Since there is no known model developed before 1871, which would classify that model as an antique, spud guns are not subject to the eased regulations regarding antique weapons. Therefore any non-combusting spud gun with a maximum projectile energy of 7.5 joules can be owned by anyone without a license, while their manufacture still requires one. The legal possession of any other such weapon requires a gun license.
A spud gun is not considered a firearm unless it fires a projectile faster than 152.4 meters per second and at a muzzle energy exceeding 5.7 Joules based on the definition of a firearm in the Canadian Criminal Code. A spud gun may be interpreted as an imitation firearm, and therefore it would be illegal to have it in possession in a public place. The spud gun would most likely be considered a dangerous weapon, and therefore if an offense is committed with it, a possession of a dangerous weapon charge could be issued. If the air powered spud gun has soft ammunition (potatoes) that splatter or bounce on impact and is kept under 100psi the spud gun is perfectly legal.
- Flaming, explosive, black powder, or living projectiles can often make a legal spud gun illegal in many jurisdictions.
- Many heavily populated areas have ordinances on projectiles and loud noise.
- While combustion cannons may be legal in a given area, stun guns, sometimes used for ignition, are illegal in some states.