Yes, it would be unethical, or at least unnecessary. It's the sort of thing you do only if you're trying to be deceptive. Otherwise...why would you?

I would disagree. Leave the original number and have something like

"Fit to #####" added so that is is clear they now go with the other gun

If renumbering barrels is unethical then there are a whole lot of unethical owners and gunsmiths out there. Don't leave out stocks forearms and most all parts. If you believe that not to be the case then there are unicorns jumping over rainbows.

It's similar to muscle/classic cars, at what point is the car original restored or did they take the VIN off of SS 454 rust bucket and rivot it to a Malibu? Without complete documentation through ownership changes there is always a chance that something has been modified or replaced.

Joe,

Personally I don't feel there would be an ethical problem with renumbering the barrels to match the gun. Just as long as you disclose it when & if you sell the gun.

Regardless of whether there are a bunch of other guns out there with renumbered barrels, it doesn't change the argument. Our jails are full of people who could easily point out that they were not the first to commit their crime.

As for the idea that it's OK 'as long as you tell the buyer'....that's great for that particular transaction. But these guns have long lives, longer than most of us. Once it's been bought and sold a few times the fact that it was renumbered becomes lost.