I'm really curious as to what problems would be fundamental to solve when trying to make an efficient projectile fit for speeds produced by a electromagnetic railgun. Firing something that fast into the atmosphere has to be problematic and I'm sure the solution to making the most accurate and speed efficient "bullet" for a railgun has to be interesting. That said... does anyone know of any links regarding these things? Or have any input/ideas or (ideally) actual experience with this area? Anything would be appreciated.