I had a similar thing happen years ago and thought I would pass it along. I had cleaned the bore of a rifle with Hoppe's no. 9, and wiped the outside of the barrel with a cloth that had some of the Hoppe's on it before I put it into my foam-lined hard case preparatory to going hunting. The next day I happened to read someplace that there was a reaction between the foam liners commonly used in gun cases and the Hoppe's. I went to look and they were right! ARRGH! One day too late! It had removed the bluing in several spots in one day. Brady

I store my guns muzzle down with the butt between clean wood pegs. No foam, no carpet, just wood.

Dave

I keep all the rifles in my safes in some sort of gun sock.

my racks are carpet covered & I have no problem but have seen this in other guys cabinets. I thnik your old sock idea would work. or pull the foam & put in cloth covered wood.

BrowningGuy- a potential problem with felt is it is hygroscopic- absorbs water from the atmosphere.

Gun Socks work great except on scoped rifles. On these I put bore down (how a gun should sleep anyway) with the stock touching carpet. Blueing reacts with foam and other rubber. I used to attach data cards to guns with rubber bands....until I learned that they will damage finishes as well.