7,9 or 8 mm?

This is no real question, as the answer is already given.
This is more an example of how difficult and uncertain this caliber nomenclature is…

I have had this cartridge for some time, now I also have a box from Kynoch stating
7,9 or 8 mm
I never heard if they provided an answer…?7komma9or8

FYI, there are at least six Kynoch hs variations using the “7.9 OR 8mm” expression . Most have the “S” caliber bullet but some are known with the smaller bullet diameter as well.

In my view it is not difficult at all.
German military called this caliber 7.9 mm. Other nations who bought armament from Germany (like China, for example) knew this caliber as 7.9 mm.
German civilian designation was, I simplify somewhat, 8 mm. So commercialy it was known as 8 mm. SAAMI even standardized it as 8 mm Mauser, although Mauser had no role whatsoever in the creation of this caliber.
After the end of WW1, Czechoslovakia obtained a lot of machinery from Germany and started production of German design rifles and ammunition. For some reason, they decided to call the identical caliber 7.92 mm. Because the Versailles treaty had removed German industry as competitor and the quality of the Czechoslovak products, the 7.92 mm figure for the German 7.9 mm caliber found widespread use.

Brad, thank you for clarifying the diameter matter of this ammunition.

as in CZ, the Scandinavian countries too often refer to the ‘8x57’ as the ‘7,92’, specially for the
military rounds. The civilian cartridges are widely called 8x57 with a host of endings