Since converted, Downing is now on the board of Metal Storm Ltd., O'Dwyer's
newly public company. Another board member is retired U.S. Admiral William A.
Owens, former vice chairman of the Joint Chiefs of Staff. 

In O'Dwyer's gun barrel the bullets are stacked like Life Savers with explosive
charges sandwiched between. Electrical contacts inside the barrel ignite the
charges in a precisely timed electronic sequence, analogous to the way droplets of
ink are ejected from a printer head. 

Easier said than done. To prevent the first round's explosion from leaking back to the
next to set off a catastrophic chain reaction down the barrel, O'Dwyer's inserts a
small metal cone into each bullet--something like an opened umbrella with the tip
pointed forward. When the explosive in front goes off, the cone is pressed
backward, minutely expanding just enough to create a seal against the inside of the
barrel. When the explosive behind it fires, the wedge relaxes and the bullet takes
off. "It may sound simple, but it's a lot harder to duplicate than it might seem," says
O'Dwyer, who has 12 patents on the system. 

Not long ago he was quickly running through the $800,000 he had raised from
selling a food-wholesale business. By 1996 he rounded up $1 million from 16
investors to pay for a six-month trial of the gun with Lockheed Martin. Lockheed
offered to take over development under a licensing agreement. O'Dwyer declined,
but the offer opened doors. 

One door led to the Pentagon's Defense Advanced Research Projects Agency,
which in March awarded Metal Storm a $10 million contract to devise a .50-caliber
sniper rifle. The Australian military is now working on a 40mm grenade launcher. 

In a recent demonstration a 36-barrel O'Dwyer gun, called Bertha (after the WWI
German monster), fired bursts of 180 9mm bullets at a rate of 1 million rounds a
minute. For comparison, Raytheon's Phalanx chain gun typically fires at 4,500
rounds per minute. 

At these extraordinary firing speeds nothing is conventional. For example, the next
round can fire before the first one has left the barrel. This has a benefit: The
pressure from the next round coming up the barrel pushes on the one in front,
adding to its range or penetrating power. 

What difference does firing rate make? DARPA's idea is that an O'Dwyer sniper gun
could fire three rounds before the shooter's aim has been spoiled by recoil. The
Navy is interested in the multiple-barrel guns as the final line of defense against
cruise missiles and suicide bombers. Instead of facing a stream of bullets from a
Phalanx, the enemy would face a cloud of hot metal. 

The matter of reloading remains murky. One way is for the user to stuff a preloaded
tube--akin to an oversized shotgun cartridge--into the barrel. Another is a preloaded
disposable barrel. 

Intriguing? That's all this invention is at this point. Metal Storm has no finished
product, just prototypes. The uncertainties have not prevented the company from
following quite an exciting trajectory on the Australian Stock Exchange, where it
listed in June 1999 following an initial offering that valued the company at $135
million. For a while the company carried a $370 million market value. It has since
settled back to $180 million, still a bit outlandish for an outfit with no sales revenues.
But O'Dwyer, who owns just under half, is doing better than most crazy inventors.