A pneumatic weapon is a weapon that fires a projectile by means of air pressure, similar in principle to the operation of pneumatic tube delivery systems. The term comes from a Greek word for "wind" or "breath" (πνεῦμα).
Comparison with firearms
In theory, pneumatic weapons have certain advantages over traditional firearms:
- The ammunition can be much simpler (and thus more compact and lighter for the same payload), because there is no need for a propellant or casing; the entire round becomes the projectile.
- Since no propellant is fired, there is no chemical residue to accumulate in the barrel or chamber.
- Because there is no casing to eject, it is theoretically possible to have a higher rate of repeat fire.
- The barrel is not heated to nearly the same extent as with a firearm.
In practice, pneumatic weapons are not as well-developed as traditional firearms and have a number of practical deficiencies:
- The weapon has to supply or be supplied with a source of very high pressure air, such as a reservoir or compressor, which adds substantial complexity and weight to the weapon.
- The action, or the mechanism by which subsequent rounds are automatically reloaded, must also be powered by the air pressure; many modern firearms re-use the energy from the propellant to accomplish this (see gas-operated reloading), further reducing the amount of work the weapon itself has to do.
Pneumatic weapons in the toy industry
The low projectile speed requirement of a toy weapon greatly reduces the amount of air pressure needed; combined with the importance of safety in the toy industry, this has led to widespread adoption of pneumatic firing mechanisms in toy weapons, where a propellant reaction is not appropriate (although other technologies, such as rubber bands, can be used).
The toy industry has produced a number of pneumatic toy weapons, which fire small, lightweight (often plastic and frequently hollow) projectiles at relatively low speeds. Airsoft and paintball guns are a popular toy that operates this way; when used with adequate safety equipment (eye protection at a minimum) these may be used in games involving shooting at other players.
BB guns and other low powered air guns, while often marketed towards the youth market, are not toys; the steel and lead projectiles they fire can readily penetrate the skin, and are capable of producing lethal wounds. While a lethal wound is unlikely due to their low power, air guns and BB guns should be used with the same precautions as firearms; eye protection for the shooter, a safe range, and an adequate backstop.