I'm reading an interesting new book titled "Hemingway's Guns, The Sporting Arms of Ernest Hemingway". In the chapter on his Winchester Model 12, a 1928 manufactured 12 ga. with a 30" full choke and solid rib barrel, it mentions that Hemingway was a big fan of Marvel Mystery Oil as a lubricant. The well used pump gun was said to be so slick that the corncob forearm could be worked back and forth with one finger ! Hemingway literally wore it out before trading it in on a newer Model 12 in 1958. Marvel Mystery Oil seems to have a pretty big following here on BITOG and while I would use more modern lubricants on my firearms, it seemed to work well in that application back in the 30's though 50's.