On regulation double rifles. It isn't rocket science. Beyond my meager skills though except for self regulating separated barrels rifles.

One of our members 4seventy, Alan Moon, regulating his own double rifles he built on shotgun actions, I think I remember his .470 was built on an UO shotgun action. He did the works including setting the barrels, test shooting, regulating then fixing, soldering the ribs in place, I think he also mentioned in the past dismantling a rifle not shooting to regulation and doing the above to fix it.

We have quite a few good gunmakers on here doing similar. It would be good for them to chime in. Even with they disagree with me.

It would be good to see Alan drop in again, He was a great regular. Running his own Far North Queensland scrub bull and boar hunting safaris in those days. Imwill give him an email.

Alex Beer?

Our USA gunmakers, there's a fair number of them.

Our French gunmakers members?

And UK gunmaker members?

I don't want to bother most of these people with an email, as they are often busy. They can chime in if they see it and choose to.