RATGUN stands for Rocket Assisted, Terminally Guided, Universal. These shells were developed by Farenday's greatest engineers to propel themselves after leaving the barrel at a constant acceleration, then seek their mark using crude active radar homing, and blast them with a dual purpose shaped charge. However, because electronics have not been sufficiently miniaturised or developed, such shells can only be produced for large-calibre artillery of at least 300mm. In the case of 46cm super-heavy naval guns, these shells can reach out targets up to 60km away.