Rail guns have a significant issue (which doesn't appear to have been overcome yet[1], unless they're just playing misdirection) that's fairly fundamental: the

Rail guns have a significant issue (which doesn't appear to have been overcome yet[1], unless they're just playing misdirection) that's fairly fundamental: the gun wastes a lot of energy on tearing itself apart. The rails would much prefer to crash into each other spectacularly than to send the projectile anywhere, and you have metal turning to plasma everywhere there is contact. It seems fairly feasible to fix the energy usage by just throwing more energy at it (and the Zumwalt demonstrates that capacity is relatively portable), but the wear on these things is going to be a massive cost even if they reduce the problem 10x from where it is now. [1]: http://www.popularmechanics.com/military/weapons/a21174/navy-electromagnetic-railgun/ http://www.popularmechanics.com/military/weapons/a21174/navy...