It depends on your ship and its heat management for an Eagle, yes the larger would turn your own ship into slag. But for Pythons, FLDs and Condas they can manage heat better and should able to fire a larger rail gun. The limiting factor should be heat though. Any ship shouldnt be able to fire their salvo of lasers along with their railgun it should be the rail takes up a large power pull or heat build so the rail user has to stop shooting his other weapons before firing his rails.