I cold blued a Browning A-Bolt barrel last week with Oxpho-Blue and made an accidental discovery . After I rubbed in 5 or 6 coats , with the steel wool and heat method , I waxed it in good shape with Butchers wax . When I looked at that barrel the next morning it was noticably darker than the day before . Don't ask me why , I'm not a chemist but I was pleased !