There’s absolutely no reason to put acid in a good barrel.
No reason at all, especially HCl................not in any of my barrels.
There are enough other good materials to remover carbon.
There will surely be some level of surface etching, whether you can see it or not; how long it might take with relatively short duration of exposure to do any damage is hard to say, but I'm not about ti find out either.
Obviously, it will attack non-stainless faster than SS.
Left exposed long enough, it will also attack chrome.
MM
