Explosives are 5 megajoules or less per kg. Forum estimates for batteries are 15.54MJ/kg+ for Eclipse Phase. So you could easily replace create a gas pressure gun with superconducting batteries. Just flash vaporize something to create the gas pressure with the electric power. In addition, there could be better gun propellants available compared to early 21st century gunpowders. That would be way more efficient than a rail/coil/gauss gun. I guess railguns could catch up in this arms race if by 10 AF somehow it was figured out how to make them much more efficient. I'm trying to think up sci-fi uses for a very efficent rail/gauss/coil effect.
—"I fear all we have done is to awaken a sleeping giant and fill him with a terrible resolve."- Isoroku Yamamoto