As luck would have it, I acquired a pair of M-S carbines in the same calibers as yours last spring, so I had time to do some load development with them. Unfortunately this year was unusually bad for deer on my place, so I only had a chance to try the 9.5X56. It performed exceptionally well, accounting for two deer with only one shot. This was entirely unintentional on my part, but welcome just the same.

This is my 9.5X56 aka rimless .375 Nitro Express 2 1/4":