In reply to: I would flute the barrels to reduce some weight
Now there is a frightening thought, a double rifle with fluted barrels. Might make the rib laying interesting.
In reply to: Id also like to convert a .410 to 303 british
I think you would be very lucky to find a double 410 which could be built into a 303. The chamber walls would end up dangerously thin IMO due to the majority of 410 doubles having tiny frame dimensions.
In reply to: The regulation does seem hard
Believe me when I say that regulation is usually NOWHERE near as difficult as (correctly) building the barrels and modifying the action.