Super magnum

Gates' .414 SuperMag.

A super magnum is a longer and/or more powerful version of a "magnum" cartridge. Although the term "super magnum" typically refers to a handgun cartridge, created by lengthening an existing straight-case design, it can also refer to rifle and shotgun cartridges, such as the .17 Winchester Super Magnum and the 312" 12 Gauge Super Magnum. In this case, it simply denotes that it is of greater power than existing "magnums" of a similar caliber or gauge, this is comparable to other designations, such as the "Remington Ultra Magnum". The most widespread of these cartridges are the "SuperMag" family of super-magnum handgun cartridges that were proposed and tested by Elgin Gates in the 1970s.