Found these the other day for a couple of bucks. I have no idea what they are other than I can make a mark on them with my finger nail. My guess is that they were for soldering. I just got a Lee bottom pour (#90009) and a Lee Magnum pot (390949). A long time ago I had a propane pot but when I dragged it out it it no longer worked. But I have a bucket of wheel weights and some other lead. Next is to get some molds to cast RB and conicals for my 44 revolvers. Unsure of these new lead bars as a friend said they might be collectible as Selby has been out of business for a while.