That would require a re-bore and rifling along with chambering.
IIRC, the 9.5x56 has a larger shoulder than the 9x57(6).

As Tom noted the shoulder expanded to .460" in his chamber - that is WAY oversize.

This rifle seems to need a re-barrel job, then it can be anything you want, within reason.

My 375/06IMP has a .460" shoulder, but seems to me, that is the "Arch" IMP case, as the "Ackley" IMP case has a .454" shoulder.