The finish on the Remington 870 Express shotguns is . . . ? It isn't bluing and doesn't look like any kind of phosphating I've ever seen. Looks almost like bake-on crinkle enamel? Does anyone know what this is? Also, I'm curious how durable it is. Vang is selling 870 barrels choked and comp'ed for a price that translates into about $80 for the barrel, which seems like a great deal -- but they're all "Express" type barrels, and I'm unfamiliar with the finish.