This has bugged me ever since I first played Fallout 2, since I didn't recall seing an in-game description anywhere. What does the EC stand for? ElectroConducting? It's just that it occured to me that Fallout 3 has EC Packs - Electron Charge Packs - that are ammo for the Gatling Laser. While the new Gauss Rifle uses Microfusion Cells. I was thinking of changing it to use the gatling laser Electron Charge Packs instead. That way it would be using EC ammo!