I came up with....
.25-35 Winchester (or 6.5 X 52 mmR in your neck of the woods)
250 Savage
.257 Roberts
7 X 57
300 Savage
They all should work just fine.
Some of the earlier m94's were chambered in 7x57 to be sold to Argentina, so there is no reason why it shouldn't work in what you have.
The case rim diameter on the 6.5x55 is slightly wider than that of the other cartridges, but there shouldn't be any problems with that. You might have to tweak the feedramp and receiver rails a little to get other cartridges to feed well.