Hi Max. Regarding the 9 x 25 mm Mauser cartridge, it was manufactured in Germany, Austria, England, France, Greece, Hungary, Italy, and unimportantly, in Australia. The Australian made rounds were from c. 1996 and were made primarily for the California Cartridge Collector’s Association as a “Show” cartridge.
I would count French and English manufacture as primarily commercial, although I suppose some could have been made under contract with foreign governments. I am not aware of any such contracts, though.
The primary user of the cartridge was Austria, although Germany made some use of it as well, as they did with most of the ammunition of Europe during the dark days of WWII. Hungary made wide use of the cartridge as well.
In Greece, use was limited to use by the Mechanized Police under “Ypourgian Asfalias,” (Ministry of Security), from which the letters “Y A” found on German (DWM) contract ammunition for Greece, and cartridges made in Greece by E.N.K. came. This agency made wide use of the MP 34 (ö), but it was short-lived, as the Mechanized Police were originated in about 1937/38, and ceased to exist after the German’s occupied Greece.
Italy made use of the cartridge in Austrian weapons and made some ammunition using a 9 mm M38 (9 Para) headstamp bunter dated 1943. Probably war needs and a relatively small use of the caliber dictated that a special bunter not be made for this ammunition. For a brief time after the war the ammunition was made commercially as well, with a typical G.F.L. commercial headstamp, but by the 1976 catalog, it has disappeared from the line.
German ammo is known from DWM with both their normal * D.M. * K headstamp, and the K DWM K 487 headstamp, as well as with the P28 coded headstamp. It was also made by Geco and RWS both with commercial-style headstamps, and with P.405 and dnh-coded headstamps.
In England, I have only ever seen Kynoch production, with commercial-syle headstamp.
As to special loadings, except for Proof Loads and factory dummy rounds, I know of no special loadings, such as high velocity loads, etc. It was primarily a SMG cartridge, and they were probably loaded to the high end, compared to say cartridges intended for commercial sale in the C.96-type Mauser pistols.
Hope this is of some help and interest.
Reference: Moss, John (Woodin Laboratory), “The 9 x 25 mm Mauser Export Cartridge,” THE IAA JOURNAL, Issue 424, March/April 2002, Pages 6 - 20.