Waterman,
While it is possible, I didn't consider any cartridge that would have been done by a German gunsmith, such as 8x60, 8x57IR, etc.This is because a German gunsmith rechambering a rifle would be required to have it reproofed, or be subject to severe punishment.Checking the boltface could provide useful info.Rim dia. of 8.15x46R is slightly less than 30-30, but some rifles will accept cases made from 30-30 w/o turning.The difference between normal 8.15 rim and 06 rim would be on the order of .020-.030", or .010-.015". This would be a little loose, but may work.
Mike