A coilgun is not a rifle as the barrel is smoothbore (not rifled). In almost all coilgun configurations, the coils and the gun barrel are arranged on a common axis. Simplified diagram of a multistage coilgun with three coils, a barrel, and a ferromagnetic projectileĪ coilgun, also known as a Gauss rifle, is a type of mass driver consisting of one or more coils used as electromagnets in the configuration of a linear motor that accelerate a ferromagnetic or conducting projectile to high velocity.