http://news.sky.com/story/1238784/futuristic-electromagnetic-railgun-tested-by-us

Very interesting that the test are now moving to sea

I read on this yesterday, it is a nice piece of tech. what I want to know is how do they keep the rails from getting damaged, a major problem with rail guns.

I'd say that they have probably solved that little issue if they have progressed to sea trials Syber, as to how....no idea 

I was saying the something, that they must of found a solution seeing it is going for see trials. If they did expect to see micro hand held versions in the near future 

I would assume the projectile is held off the rails by magnetism. Effectively no friction/wear. The realities of life and air resistance would cause loads of friction though. The limiting factors would be how much power you can give it and what Gs the projectile can take. Power would severely limit a hand held device.
As for guiding something travelling at Mach 7...