Got my copy of recreating the double barrel muzzleloading shotgun.

[8Ga.]

A properly regulated double gun will have both barrels hitting the same point of impact at a specific distance. The shooter who knows that distance can then compensate for greater or lesser ranges. This is obviously more critical for a double rifle, but at a given distance shot patterns should overlap also. In an unregulated gun you may find your are consistently more accurate with one barrel over another.

Ya, I didn’t know that’s called regulated. I just assumed that if the barrels were made absolutely to spec they should be fine. I had some ideas on how to make them adjustable, but that will be after I actually accomplish making one in the first place.

 

[muzzlecap]

I have a Grainger percussion double barrel I picked up several years ago. Bought it online. I knew it had been restored just from the pics. However, when I received it, it took me a few days to realize that it has a set of barrels from a more modern breech loading shotgun. The whole gun was done very well and I'm sure it was no easy task fitting the barrels to this gun. Whoever did the work knew what they were doing. So yes it can be done but be prepared for the work involved.

 

[shorthair]

A properly regulated double gun will have both barrels hitting the same point of impact at a specific distance. The shooter who knows that distance can then compensate for greater or lesser ranges. This is obviously more critical for a double rifle, but at a given distance shot patterns should overlap also. In an unregulated gun you may find your are consistently more accurate with one barrel over another.

Regulating barrels is a true art form, which the old Btits figured out a few centuries back and still train apprentices in for several years before they can do it on their own. If you need evidence just check prices on current bespoke British doubles.
I've never attempted it but I do know that involves a lot of trying and soldering of the ribs removing and adjusting with test firing before you are done. Sure would not be worth my time and effort when I can buy a kit for not that much $.