Handheld railgun, equipped with a high-density energy storage system to supply the power-hungry firing mechanism
Railguns use electromagnetic forces to accelerate projectiles using a pair of rails and a sliding armature. If sufficient energy is used, the projectile can achieve very high velocity, exceeding many other projectile weapon systems in this respect.
Railguns are often very large weapons, requiring significant amounts of power. Warships and orbiting weapons platforms often have a number of very long railguns pointing in various directions, drawing respectable amounts of power from the ships' reactors to launch extremely fast missiles with ultra-high levels of acceleration.
Smaller ships, fighters, ground vehicles, mecha and war-drones by necessity have shorter railguns and smaller reserves of power, so the projectiles from such sources are somewhat slower. Slower still are the projectiles launched by handheld railguns, which as weapons are comparable to hand-held lasers, gaussguns and guns using chemical propellants in many ways, but are very effective as kinetic weapons, especially in vacuum.