Bokmal found an old Sako 9,3x57 box for me in Finland. first time that I have this load in my hands, never see it in the list's of cartridge collectors here before.
I don't know when Sako was making the 9,3x57, have only one book from 1973 where its noted as "available"

the Sako round have the same OAL with its 255 grains bullet like the Norma cartridge with its 286 grains bullet

9x57
9,3x57
9,5x56

if there was ever a doubt about it that the 9,3x53R is the rimmed version of the 9,3x57: same bullet, powder load and velocity - like twin's
the 9,3x53R box is much more remarkable, will show it in my mosin post