"I think the first application of rail guns will be to shoot stuff into low orbit. I cannot see military applications anywhere soon... for the reasons mentioned above: military applications need mobile electrical power, and the rails wear too quickly.
However, there is plenty of robust bulk material that needs to get into orbit (fuels, water, food, or mechanical parts for maintenance of ships up there)... if packed in the right way, all that can withstand massive G forces, so it can be launched in a simple shell. Cheap, efficient, fast."
the US Navy just got a 32 Mega Joule rail gun to mount on a ship and to my knowledge they are looking for a cheap replacement for the Tomahawk cruse missile
