An electromagnetic gun is a type of weapon similar to a standard firearm or other gun, except it uses electricity and magnetism to create the force that propels the projectile from the gun. Standard firearms use ammunition that includes gunpowder, which is used to create a small explosion that creates the force to fire the bullet from the casing. An electromagnetic gun uses an electric current to generate a magnetic field, which creates the force necessary to propel a bullet or other projectile out from the gun at incredibly high speeds.
Also called a rail gun or EM gun, an electromagnetic gun is typically quite large in scale, due to the energy requirements needed for such a weapon. While efforts have been made to scale down these weapons, models as of 2011 are more like canons or mounted artillery weapons. An electromagnetic gun has a pair of electrically conductive rails, hence the alternate name, held near each other but not touching. A power source is then connected to these rails, typically a capacitor or other electrical power supply.
Depending on the design of the electromagnetic gun, an armature may also be present between these two rails against which a projectile can be placed. This armature itself can be conductive or the projectiles used with the gun may be conductive; in either case, this allows the circuit through the two rails to be completed. Once this is done, the two rails become electrically charged, in turn producing a magnetic field. This field produces a tremendous amount of energy within the electromagnetic gun, which then pushes the projectile down the barrel of the gun and out toward a target.
The high amount of energy produced by the electromagnetic gun, however, can be so intense that the rails on many early models would melt and have to be replaced between every shot. These guns also require a very large power supply to function, which makes the use of handguns or even rifles designed as rail guns cost-prohibitive. Larger rail guns, however, have been designed and are being developed for use as large-scale artillery for battleships and other vehicles.
If current development continues, an electromagnetic gun may be constructed by around 2016 that will be able to fire a projectile more than 100 miles (160 km) at a rate of over seven times the speed of sound. These projectiles would be so powerful that they would not even use an explosive payload. The kinetic energy from their speed would be enough to destroy bunkers, tanks, and other targets on impact.