Hi Boltman thanks for your reply,
since I wrote this post ar the weekend I have had a word with the gunsmith who has worked on a few projects for me over the last few years but he has never worked on a Ross before.
He reckons on finding another 220 Swift action if I must have a custom built 220 Swift.
I thought that with the Swift case being pretty close to the 303 at the rear end it might be a practical thing to do with this chopped around Ross Rifle.
Regards.