oh yes it is very real. the concept is obviously decades old but only recently have reasonable design's been found whereas it would be efficient on a mobile platform. im pretty sure it has been field tested from a mobile platform tbh i read something maybe a year ago on it.
the main dead point of the design is not being able to mount anything but a slug... delay-drop/gas/thermo(bunker) or standard HE aren't feasable unless you want your billion dollar railgun to blow your multi-billion dollar ship
its unrivaled in theory at engaging single target's.. i.e naval warfare (if such a theatre of war was ever to come about again) it would rip through any ship like jelly. most likely sinking it. and ofc anti-air. but against land targets it falls short. ya need thermobaric or HE shells for ye olde mass destruction
