Gentlemen - I am not so sure that the entry on page 74 of “Bergmann’s Ruckstosslader” referring to a 9 mm cartridge is a misprint of any kind. For me, the defining part of the entry is that the cartridge was referred to there as “Patrone No. 6 Cal. 9 mm…” The entry for the 9 mm Patrone No.6 in the DWM Case Register is for a 9 mm cartridge.
We know that there was a Bergmann No. 6 Pistol, also referred to as “Model of 1899.” Specimens of this pistol are most know with a Swiss connection, and are said to have been made in caliber 7.5 mm (DWM No. 460A and 7.65 mm (DWM No. 475). The 9 mm Bergmann cartridge, the first version from DWM being with a longer overall length than the later 9 mm Bergmann-Bayard and with a headstamp of * D.M. * K. The assigned case number was 459, which appears on a later headstamp which, although has the same weight bullet as the longer D.M.K. version, has a shorter overall length. My specimen of the 9 mm No. 6 cartridge has an OACL of 35.29 mm (1.3895") The first “Mars Cartridge,” as they as also known, actually is slightly longer than a 7.8 Bergmann round or a 7.63 Mauser round. I wish I still had my Bergmann Model 1903 Mars Pistol, to see if the D.M.K. cartridge will even fit the magazine. I would doubt it would, however.
In a fine article on Bergmann Pistols, “The Bergmann Pistols,” by ed Buffaloe, he theorizes that the No. 6 (1899) pistol “may have been a hybrid of the No.4 and No. 5 pistols…”
The point here is that according to the case register, the 9 mm Bergmann no 6 cartridge precedes the other two cartridges known to have been chambered in the Bergmann Pistol No. 6 (Model of 1899). I am not sure that many people have seen even a picture of a Bergmann No. 6 pistol. They are likely the rarest of all Bergmann pistols. We know that in 1900 two No. 6 pistols were tested in the previously mentioned calibers DWM 460A and 475.
There had to be a reason for the production of the 9 mm No. 6 cartridge by DWM, which seems to have taken place c.1899. There must have been pistols chambered for it and capable of handling the 9 mm Mars cartridge. Further, we must remember that a finished pistol design seldom happens overnight. It took the U.S. Government 6 years of looking at the 1905 Colt .45 ACP Pistol and later prototypes models to get to the M1911. A simple blowback pistol like the Russian Makarov was 4 years in the making before adoption, 1947-1951 and another two years before serial production for issue took place.
It is likely that the development of the 1903 Bergmann Mars pistol started at least as early as 1900, and perhaps a year earlier.
None of this is hard evidence of anything, I fully admit. But when you add up all the little bits of information, they point to the great possibility that the Bergmann 9 mm No. 6 cartridge existed several years before 1903.
Just my opinion, and one I admit to not being wedded to. Documentation to the contrary would change that opinion quickly. Unfortunately, to date,we have to rely on what little documentation there is, along with a lot of emperical evidence surrounding the Bergmann Patrone 9 mm No. 6.