US Navy's Newest Sci-fi Weapon - the Railgun
Once existing only in the imaginations of gamers and sci-fi geeks, the railgun is now a reality. The US Navy set a world record by firing a projectile from its advanced electromagnetic railgun at a velocity of 8,270 feet per second (5,640 mph), and the gun is only firing at a third of its potential power.
According to Wikipedia: "A railgun is an entirely electrical gun that accelerates a conductive projectile along a pair of metal rails using the same principles as the homopolar motor. Railguns use two sliding or rolling contacts that permit a large electric current to pass through the projectile. This current interacts with the strong magnetic fields generated by the rails and this accelerates the projectile."
In other words, a rail gun uses electromagnetism instead of a chemical propellant like gun powder or cordite, and has 2-3 times the velocity of conventional cannon.
The railgun fires a kinetic sabot round. The sabot is the casing added to small projectile to make it fit the bore of the gun barrel.
The projectile is a kinetic round that travels at incredibly high speed, and doesn't require any explosive to destroy its target. The round impacts with such force that it appears an explosion has taken place.
Here's an official Navy video of the railgun in action: