Just this afternooon I re-blued a Swedish Mauser project gun I've been working on for longer than I'd like to admit. I used Brownells Dicropan T4. I had previously removed the old bluing with Birchwood Casey's rust and blue remover and polished the metal with varying grits of wet/dry sandpaper down to 600 grit. Foloowing the directions on the bottle and about 4 coats later, the finish absolutely amazes me. I never dreamed that a cold blue job could look that good. Best part is the T4 only costs about 10 bucks. Needless to say...very happy with the results.