Hi Everyone thanks for all the suggestions and offers of help.
I had thought my choices were going to be limited to .22, .38 and 30-30 but you have opened up many more possibilities.
Would 30-30 work or does it develop too much pressure?
6,5x57R would be pretty amazing and it might be possible to find some old Swedish Mauser barrels.
I will try to post some pics of the donor action and you can let me know what you think.