[quote=@MetalLover]
<Snipped quote by Willy Vereb>

Yeah no, we do not have Hand Carried railguns. The compact power source has not been found, yet.
[/quote]It was found in the modern world already. It's called compact carbon-nanotube based hydrogen fuel cells.
Also by pure scaling off from the tank-mounted railguns we already should have the power source to feed 1-10kJ range railguns with relative ease.
Also we already have powered exoskeletons so that's another nail in the coffin for the lack of compact power sources.