WASHINGTON -- The phrase "faster than a speeding bullet" just took on a whole new meaning.

"An electromagnetic rail gun is a gun that uses just electricity -- no gun powder -- and, oh, by the way, can shoot a projectile like this, well over 100 miles at Mach 7," said Rear Adm. Matthew Klunder, the Chief of Naval Research, which developed the rail gun. "Seven times the speed of sound."

Rear Adm. Matthew Klunder shows the projectile. CBS News

An electromagnetic pulse propels a projectile down the barrel, creating a fireball of molten steel. The projectile sheds its steel cladding, and, in video released for the first time Monday, it smashes into a dummy warhead that represents an incoming missile. An explosion is caused by the sheer force of the impact.

"This is a lab gun, and it shoots a slug about this big," Klunder said, holding up a slug. "So think about that. A slug that big -- a slug that big going Mach 7 puts a hole through six half-inch steel plates this big. Just this little slug."

"There's not a thing in the sky that's going to survive against that," Klunder added.

The hyper velocity projectile, can also be seen going through three reinforced concrete walls. The Navy already has missiles that perform the same feats, but they cost millions of dollars each.

The projectile put a hole through six half-inch steel plates. CBS News

"This costs right here about $25,000," Klunder said.

Both the cost and size -- it weighs 23 pounds -- mean they can be bought and stored aboard ships by the hundreds.

"Someone may be sending a multimillion-dollar missile at us, and I'm going to take it out with a $25,000 projectile round," Klunder said. "I'll take that trade every single day."

But not so fast. The first rail gun won't go to sea until 2016, and then only aboard a cargo vessel for testing. It will be the end of the decade before the rail gun appears on warships.