HEADING : Electromagnetic gun
An electromagnetic gun or rail gun as it is more commonly know is a military weapon that uses electromagnetic force to operate. It consists of a sliding amateur that is located between two conductive rails. It is used to shoot projectiles at very high velocity. They were designed to decrease the use of propellants for weapons artillery eg. Rocket propulsion grenades. A design of the gun is hsown below:

The power supply used for this device needs to be of a very high capacity to suplly the high amperage needed to generate the high magnetic field needed to propel the projectiles.
The rails are the stationary part of the gun and are constructed of lengths of conductor material of which the preferred choice is usually copper.
The armature is usually the moving part and the gap between the rails is linked with this component. It is usually comes in two designs; a solid conductor or a conductive sabot(Projectile housing/carrier).