Remington40x,
Skeettx is correct that your rifle is chambered for 9x58 1/2 R S&S. The confusion comes from two things. First, the most common source of donor brass to make cases from is the 9.3x72R.Cases made from this brass usually retains the 9.3 head stamp. Second, I have a friend that has an ED. Kettner double rifle made by Sauer in this caliber before 1912. The bore diameter is marked in the pre 1912 system(gauge) and is shown as 118,35 which is also found on a great many 9.3s of different case lengths. This is a pretty uncommon, but fun, cartridge that makes a useful deer rifle. In power, it is very similar to the 360 2 1/4"( 9.3x57R), but rather than a neck, the case is straight tapered like the other more common S&S cartridges( 8x48/58R, 6.5x48/58R, 6.5x40R, etc).
Mike
