Many of the shots were fired to research and test different barrel designs and to evaluate the damage generated by the gun.
The first shot was launched more than four years ago, in March of 2007, and the railgun has since been enhanced from an energy level of 0.5 megajoules to currently 1.5 megajoules. In comparison, "a one-ton vehicle moving at 100 mph has approximately one megajoule of kinetic energy," the U.S. navy explained.
The railgun developed by the Navy launches and accelerates hundreds of conductive projectiles along pairs of metal rails using the effects of a strong magnetic field. The Navy railgun is rumored to accelerated a 7-pound projectile to a speed of 2.4 km/s or 5400 mph. However, rumor has it that velocities of up to 3.5 km/s have been achieved. In comparison, projectiles fired from an M16 rifle top out at 0.9 km/s. Navy officials said that the range of a railgun is up to 20 times greater than that of conventional weapon systems. A projectile could reach a target 290 miles away in less than 6 minutes and impact it with massive force. The idea is to potentially replace extremely expensive Tomahawk missiles, at least in some scenarios.
"A railgun weapons system must be able to launch hundreds of projectiles and withstand extreme pressures, currents and temperatures," said NRL Commanding Officer, Capt. Paul Stewart in a prepared statement. "Today's firing of the one-thousandth shot demonstrates Navy researchers are steadily progressing toward achieving that goal, developing a more effective and efficient future ship combat system."