NOTE: Interestingly, this came from DowJones.com..

Meet The Supergun;

A warning siren bellowed through the concrete bunker of a top-secret Naval facility where U.S. military engineers prepared to demonstrate a weapon for which there is little defense.
Officials huddled at a video screen for a first look at a deadly new supergun that can fire a 25-pound projectile through seven steel plates and leave a 5-inch hole.
The weapon is called a railgun and requires neither gunpowder nor explosive. It is powered by electromagnetic rails that accelerate a hardened projectile to staggering velocity--a battlefield meteorite with the power to one day transform military strategy, say supporters, and keep the U.S. ahead of advancing Russian and Chinese weaponry.
In conventional guns, a bullet loses velocity from the moment the gunpowder ignites and sends it flying. The railgun projectile instead gains speed as it travels the length of a 32-foot barrel, exiting the muzzle at 4,500 miles an hour, or more than a mile a second.
"This is going to change the way we fight," said U.S. Navy Adm. Mat Winter, the head of the Office of Naval Research.
The Navy developed the railgun as a potent offensive weapon to blow holes in enemy ships, destroy tanks and level terrorist camps. The weapon system has the attention of top Pentagon officials also interested in its potential to knock enemy missiles out of the sky more inexpensively and in greater numbers than current missile-defense systems--perhaps within a decade.
The future challenge for the U.S. military, in broad terms, is maintaining a global reach with declining numbers of Navy ships and land forces. Growing expenses and fixed budgets make it more difficult to maintain large forces in the right places to deter aggression.
"I can't conceive of a future where we would replicate Cold War forces in Europe," said Deputy Secretary of Defense Robert Work, one of the weapon's chief boosters. "But I could conceive of a set of railguns that would be inexpensive but would have enormous deterrent value. They would have value against airplanes, missiles, tanks, almost anything."
Inside the test bunker at Dahlgren, military officials turned to the video monitor showing the rectangular railgun barrel. Engineer Tom Boucher, program manager for the railgun in the Office of Naval Research, explained: "We are watching the system charge. "We are taking power from the grid."
Wires splay out the back of the railgun, which requires a power plant that generates 25 megawatts--enough electricity to power 18,750 homes.
The siren blared again, and the weapon fired. The video replay was slowed so officials could see aluminum shavings ignite in a fireball and the projectile emerge from its protective shell.
"This," Mr. Boucher said, "is a thing of beauty going off."
The railgun faces many technical barriers before it is battle ready. Policy makers also must weigh geopolitical questions. China and Russia see the railgun and other advances in U.S. missile defense as upending the world's balance of power because it negates their own missile arsenals.
The railgun's prospective military advantage has made the developing technology a priority of hackers in China and Russia, officials said.
Chinese hackers in particular have tried to penetrate the computer systems of the Pentagon and its defense contractors to probe railgun secrets, U.S. defense officials said. Pentagon officials declined to discuss the matter further.
The Navy began working on the railgun a decade ago and has spent more than half a billion dollars. The Pentagon's Strategic Capabilities office is investing another $800 million--the largest share for any project--to develop the weapon's defensive ability, as well as to adapt existing guns to fire the railgun's high-tech projectiles.
Some officials expressed concern the technology has commanded too large a portion of resources and focus. "This better work," one defense official said.
The age of the gun faded after World War II, hampered by the limited range and accuracy of gunpowder weapons. Missiles and jet fighters dominated the Cold War years, prompting the Navy to retire its big-gun battleships. The railgun--and its newly developed projectiles--could launch a new generation of the vessels.