Is my rib aluminum, or steel like the barrel? I tried the bluing, and it helped a little, but the ding is still quite noticable. It's like three of the tiny little ridges on the rib got flattened out. I'm thinking it's a softer material than steel, or the ridges wouldn't have flattened so easily. So, perhaps the rib is aluminum, and maybe I should try the Aluminum Black?