The Navy is researching rail guns because they would weigh less than conventional ones, and since they rely on electromagnetics to fire rounds, you wouldn't need a big, dangerous pile of explosives stored in a magazine. All of that means a lighter ship, and a much more deadly ship: a combat-ready rail gun would be able to fire Mach 5 projectiles over 200 miles with pinpoint accuracy, hitting 5 meter targets.

Yesterday's test firing at the Naval Surface Warfare Center Dahlgren Division used just some of the potential 32-megajoules the laboratory test gun is capable of, and that's only half the 64-megajoules the Navy is aiming at for the final weapon. Expect even more dramatic videos, sometime soon. [Navy Times and Danger Room]

A rail gun, to refresh your memory, is one that relies on precise and extremely juiced electromagnets to thrust the projectile, rather than ever increasing amounts of packed and wadded gunpowder or other fuel. Explosives are, after all, dangerous. On a ship, they either blow up or get wet, and either way that's just bad.

The device BAE Systems shipped to the U.S. Naval Surface Warfare Center in Dahlgren, Va. is the 32-megajoule Electro-Magnetic Laboratory Rail Gun (32-MJ LRG for short, but we'll call her "Julie"). It is about four times as strong as the last generation of rail guns, but demands 3 million amps of power per shot—enough to drain your Metal Gear's battery in a heartbeat. You'll notice the word "laboratory" stuck in there. Real-life rail guns have kinks that still need to be worked out:

Effective rail guns will require a major breakthrough in capacitor technology between now and 2020, as well as a way to keep the barrels from being shredded by each high-velocity shot.