Railguns, also known as rail guns or rail cannons, are a class of electromagnetic cannon, used when infantry fielded coilguns (though simply called Gauss rifles and Gauss pistols in game, both coilguns and railguns are Gauss guns) are not powerful enough. They fire much larger rounds compared to coilguns, and are anti-materiel as opposed to anti-personnel.
↑Museum of Technology placard: "This is the only known prototype of the X277 "Viper" Magnetic Rail Cannon developed for the U.S. Military by West-Tek. Also commonly referred to as a "Railgun", the weapon uses energy cells to propel a depleted uranium round across a series of magnets discharging it at extremely high velocity. Deemed too costly to produce on a mass scale, the project was abandoned in 2044. On loan from the International Ordnance Museum, these cases display the various types of weapons and ammunition used by the military in past conflicts all over the globe."