That’s the sort of thing, but what I have in mind is something like the old .303 to .297/.230 Morris Tube so as to be able to slip a rifled liner into a converted to .410 Rook Rifle to make a usable small game rifle without losing the .410 option.
It should be do-able, but assuming a .375” outer diameter for the tube it would need a fairly small bore to preserve wall thickness although the .410 chamber section would support much of the peak pressure.
It would also need to be sufficiently low pressure to be safe. Perhaps .22 WCF?
