The Mateba 6 Unica is the culmination of a series of revolver development by Italian designer Emilio Ghisoni (1937-2008). The Unica 6 is one of only a few self-cocking revolvers to see commercial production and sales (the other two being the Union and the Webley-Fosbery). It was available in .357 Magnum, .44. Magnum (like today's example), and .454 Casull. All three could be used with the associated Special ammunition with a recoil spring swap. In addition, the Unica 6 fired from the bottom chamber of its cylinder, which allowed it to use an open frame design with powerful magnum cartridges (Ghisoni was also involved in the other common revolver with this feature, the Chiappa Rhino).