The Mann pistol is a German pocket pistol.
The aim of the Mann's design was to create a simple, light-weight, reliable design. However, Mann did not want to use use blowback as it made the gun heavy.
Design DetailsEditThe Mann did not have a breech locking mechanism, so the gun's operation had to slow down enough to eject the cartridge. Mann chose a circular chamber groove for the gun, which slowed the cycling down enough, where pressure in the barrel forces the cartridge into the groove, delaying the action. The gun also had barrel retention, which was innovative at the time.
An interesting quirk about the Mann was that it was supposed to bulge cases, which would usually be a bad thing on a modern firearm.