OK now I went and did it.. Found a pair of 45 cal. Adam and Bennett barrels (F99 countour which is pretty much 1/20" straight). Then a buddy had a "wall hanger" double shotgun which turned out to be a 12 ga JP Claybrough with
28" damascus tubes. It's a little rough but not bad, it is all there for the most part and it locks up tight. Cost me all of a $50 bill to get it.
So the plan is to:
Chop the shotgun barrels to 24"
Turn the barrel blanks to go into the shortened shotgun barrels which
includes turning one end to the same dimension as a 12 ga shell.
Chamber the barrels in 45/70
Cut extractor slots and make extrators to work with the shotgun extractor bar.
Thread the other end and make caps that will seat against the muzzle of each shotgun barrel.
Re-bush the holes in the action for the firing pins.
Turn down the current firing pins to fit the new bushing.
Make up a set of express sigts and attach them to the rib.
refinish the stock.
Barrels would slide in from the back and the caps would go on the front to hold the barrel in place. These front caps would have the threads cut slightly off center (a few thou.) to allow me to regulate the barrels.
Finally I may have my english style double rifle in 45-70. I know I can't hotrod the loads but it should be good for any of the cast bullet loads out there I would think. The modern steel barrels should eliminate any issues with the damascus tubes that are hiding them. The face of the action is at least 0.25 to 0.375 inch thick so there is plenty of meat there.... And a hammer gun to boot....
OK any thoughts????