As this M-Sch Stutzen was proofed in 1952, still without a side safety and swept back bolt handle, it is a model 1950. So the most likely chambering is the common 8x57 IS, though some 8x60 S ones were built in rifle form at that time too. Carbines or rifles for the old proprietary 8x56 M-Sch, 9x56 and 9.5x57 were not made post-WW2 any more.