Spot-on Bramble,

Many years ago (like about 20) I had a Cogswell & Harrison double in 475NE (3-1/4" straight) which I bought relatively cheap because it was off the face. We had a good Industrial Hard Chrome Plating business not far from where I worked, so that was where I took it. They hadn't done any firearm work before, but after a little discussion, we ended up doing exactly as Bramble has described. I fitted it back with diamond files and that rifle was as good as gold, tight as a drum. I used it considerably for quite some years and then foolishly sold it. An amazingly accurate double rifle that one was too.

If one has access to a GOOD Industrial Hard Chrome Plating business, I would suggest this procedure.

Best

Alex

alexbeer.com