Store all your firearms in a cool, dry place, with a dehumidifier running nearby for good measure if there is any hint of moisture (as in a basement). But if you pull out one of your guns and see a few blotches of rust on barrel or receiver, here’s an interesting way to remove it.
From Range 365: The trick…is finding a penny minted before 1982, which were 95 percent copper and 5 percent zinc.
To start you need some light oil (good old 3-in-1 will do just fine), a medium brass-bristle cleaning brush, some paper towels, and your pre-1982 penny.
Pick a spot to start, put some oil on the metal, rub the penny over the area, and wipe clean with a paper towel. Repeat until the rust is gone. Use the brush to scour the rust out of areas with small crevices, like a shotgun rib.
The copper in the penny is softer than the steel, so light pressure will wear away the rust without scouring the steel or the remaining bluing.
Great tip Mike. Going to attempt this over the weekend on an old shotgun I received as a gift from my father-in-law. It belonged to his grandfather, so it’s been in storage for some time now.