Talk about an unusual chambering!
In all my [shooting/hunting] travels I might have heard of ONE individual owning such a gun. A buddy of mine knew another hunter who had an improved Whelen boltgun, but Wade didn't know if it was an A.I. or a Brown-Whelen!
But if you went forward with this idea, sure you want to shell out $200-$300 for dies in a singleshot? Should figure at least $150-$200 minimum.
Why not instead look at the company that designed the .338 Hawk? (out of Wyoming). Don't recall their corporate name, but if they designed a .35-cal built on a .30/06 case, I'd be curious what their's looks like before I settled on what the finished round and rechambered barrel is supposed to lok like.