Engineering:5mm Bergmann

Short description: German centerfire pistol cartridge

5mm Bergmann
Type	Pistol
Place of origin	German Empire
Production history
Designer	Bergmann
Designed	1894
Produced	1896–1900
Specifications
Bullet diameter	.2 in (5.1 mm)
Ballistic performance
Bullet mass/type Velocity Energy 35 gr (2 g) FMJ 580 ft/s (180 m/s) 26 ft⋅lbf (35 J)
Source(s): "Textbook of Automatic Pistols"

The 5mm Bergmann is an unusual centerfire cartridge produced for very early self-loading pocket pistols. The case is steeply conical and headspaces on the conical case walls. Early versions (sometimes called the 5 mm Bergmann Rimless) were made without any rim or extraction groove; and relied upon blow-back for expulsion of the fired case from the chamber. Later Bergmann pistols provided an extractor requiring a groove which produced a semi-rimmed case. The long bullet was inadequately stabilized and tended to tumble in flight.