Read this first:

http://forums.nitroexpress.com/showflat....amp;Search=true

IMO the unrimmed ammo is quite rare. The stopping power seems to settle between 8x64S and 8x68. Mr Speed says that ammo need magnum-lenght action and some Mauser Model B rifles has been made for this caliber. Down in the middle is rimmed version, Speed`s first book has only one black & white foto of unrimmed version and it looks very similar:

From left to right:

.30R Blaser - 8x75RS - 9,3x74R