"8x60 MAGNUM" simply was the Austrian designation of the German 8x60S, .323" bullet. In the 1950s RWS cartridge boxes had both designations, see photo: [url=http://i1018.photobucket.com/albums/af303/kuduae/8x60S2.jpg]
The German army went to the .323" diameter bullet in 1904 with the introduction of the "Spitzgeschosspatrone" = pointed bullet cartridge, hence the monicker "S". The "I" = .318" diameter remained popular in Germany as the "civilian" diameter until WW2.
The Austrians, on the other hand, used the .323" diameter from the start, at least since their M95 8x50R Mannlicher aka .315 Mannlicher(for the bore diameter) aka .315 IOF (Indian Ordinance Factories) and the M1908 8x56 Mannlicher-Schoenauer. As they never used pointed bullets in .323" diameter in their military cartridges, they did not use the "S" monicker either. Instead, when they introduced the 8x60 in the 1925 Mannlicher-Schoenauer, they used their regular .323" diameter exclusively. As ballistics were vastly improved upon their "standard" 8x50R or 8x56M-S, they applied the "MAGNUM" name.