The development of electromagnetic (EM) railguns could revolutionise warfighting capability, with the potential to deliver lethal firepower to ranges in excess of 200 nautical miles (370 km; 230 miles). An EM gun uses an extremely high current flow to create an electromagnetic force that will propel projectiles at speeds greater than Mach 7.0. and destroy targets through the sheer force of impact (i.e. without explosives being used). On 16 January 2007, a test shot was fired at the US Naval Warfare Center Dahlgren Division, with a muzzle energy of 7,4 megajoules and an achieved velocity of 2,146 m/s (7,040 ft per second). Ultimately, such guns will be provided for ships, as the absence of gunpowder in the weapon means that the risk of explosions on board is eliminated and there would also be increased magazine capacity, improved safety and reduced cost and logistic requirements. They are expected to replace the standard 12.5-cm (5-in) naval gun in due course.
One megajoule is the equivalent to 737,582.5 foot pounds or the energy needed to produce one watt of electricity for one second. However, on 31 January 2008, the same test centre demonstrated an EM gun at a record power level of 10 megajoules of muzzle energy. The EM gun tested has a reported capacity of 32 megajoules, but increases of energy are being made slowly within a defined test programme.
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