The US Navy has completed another round of tests in its quest for the ultimate ship’s gun: a functional weapon based on railgun technology. The next step is to take the gun to sea for tests aboard the USNS Millinocket (JHSV 3), a high-speed transport catamaran built by Austal. “We’re beyond lab coats—we’re into engineering now,” said Chief of Naval Operations Admiral Jonathan Greenert during a speech at the Navy League’s Sea-Air-Space Expo in National Harbor, Maryland.

The railgun is just one of a number of high-energy weapons being tested by the Navy. The first to go to sea will be the Laser Weapon System (LaWS), which will be put to sea aboard the USS Ponce late this summer, the Office of Naval Research confirmed yesterday.

But the LaWS is a relatively low-power directed energy weapon intended to take out drones, small boats, and other threats at fairly close range. The electromagnetic rail guns, which are being tested at the Naval Surface Warfare Center’s Dahlgren Division in Dahlgren, Virginia, are capable of launching a projectile at speeds over Mach 7 and would have ranges exceeding 100 miles. A 23-pound projectile flying at Mach 7 has 32 megajoules of energy. That’s roughly equivalent to the energy required to accelerate 1,000 kilograms (1.1 US tons) to 252 meters per second—or around 566 miles an hour.

A video released yesterday by the Naval Sea Systems Command shows the completion of railgun test shots against a number of targets, including a dummy missile warhead and multiple reinforced concrete walls. The Navy has tested two railguns—one built by General Atomics, the makers of the Predator drone, and one built by BAE Systems. Both will be put aboard the Millinocket this summer for demonstration, but the Navy will choose just one for the final test.