The 30 Carbine is listed here for continuity from the Erlmeier, Brandt records, but it was a military cartridge developed during the early years of WW2. It was however loaded in handguns as can be seen by the Kimball Arms Company semi-auto. The pistol used a series of cut rings in the chamber that would delay the extraction of the fired case long enough for the pressure to drop and cycle the slide. But because of severe case pressure about 238 of the supposed 250 guns manufactured were destroyed by this before the idea was put to rest. The full detail on the history and development of the 30 Carbine is discussed in the military section. (Erlmeier, Brandt Ref. 318)
