That's an interesting idea. I like it, though I think I'd need to add a different perhaps lighter version of the railgun. I'd like the one in the game right now to be as powerful as it is currently without nerfing it, it'll just be a late game weapon.
In fluff, could be some form of super-shock ablative armor? It'd make sense since railguns and other super high impact weapons have been deployed.
Cool! I could see it.