Clean and degrease the barrel,Apply Ammonium chloride and distilled Water solution,stand in warm area until rusted,Boil for ten minutes in rainwater,Using 0000 Steel Wool rub off the Rust that has changed from Feric Oxide (Red) to Fero Feric Oxide (Black).Repete these operations until you have a deep black,Wash with clean Water, heat barrel and apply lubricating oil,Allow to stand for a couple of hours before wipeing off excess oil.For Browning do not boil just scald by pouring boiling water over the barrel.
P S.Plug off the Barrel at each end before starting.