*Blink*
...But a pile driver is called that because it drives piles, pillars, pikes, and other building-related material into the ground. So it's just a fancy way of saying it's a mass driver? O_o And if so, isn't that the same thing as a Railgun? Both are accelerating mass to high velocity in order to deliver excessive kinetic energy on target. Unless the "pile launcher" uses a different motive mechanism than electromagnetism, in which case I could see the difference.
I mean, don't get me wrong, I likes me the idea of guns that shoot giant spikes of tungsten at high mach numbers, but when you've got that AND railguns, it just seems redundant. *Shrugs*