You would likely have difficulty feeding cartridges through the magazine.

Otto Schoenauer's wonderful rotary magazine works flawlessly when fed with cartridges that are of the exact dimensions for which the magazine was machined. Cartridges outside of original specifications would likely jam.

These are proper dimensions of the 9.5X57 / .375 Nitro Express Rimless:

You won't need a barrel to find out.
Get hold of five 9.3X57 cartridges and try cycling them through the action.