Spud Gun - Launcher Types

Launcher Types

All spud guns propel projectiles down their barrels using pressurised gas in the same manner as a firearm (although at a much lower pressure). There are four basic ways that spud guns may achieve this:

• By the combustion of a gaseous fuel-air mixture; this is generally called a combustion launcher, and its pressure is limited primarily by the energy density of the fuel-air mixture (less than 100 psi (0.7 MPa) with all safe fuels).
• By the release of compressed gas (normally air) through a valve; such a launcher is typically referred to as a pneumatic launcher, and its power is limited primarily by the pressure of the air supply, be that from a compressor, manual pump or bottled gas.
• By the explosion of a dry ice bomb placed in the pipe before the projectile, generally referred to as a dry ice bomb cannon, these are limited in power by the materials and size of the dry ice bomb but firing pressures can be around 200–300 psi (1.4–2.1 MPa).
• By the combustion of a pre-pressurised fuel-air mixture; this is called a hybrid launcher, and yields higher pressures than that of a normal combustion spud gun, limited only by the construction of the launcher (generally a few hundred pounds-force per square inch).