Blacking.

[Frank Rabbets]

I've just reblacked an air rifle barrel. What a nightmare and very dangerous. I made a long steel tank to hold a solution of caustic soda and saltpetre. I fitted a full length tube underneath drilled with holes to form gas jets to boil the solution. I then very carefully lowered the barrel in and boiled it for 20 minutes. I would say it was sort of 60% successful. The barrel is blackish blue but it looks very thin. Also I think it needed polishing to perfection first.

Calling sodium hydroxide "caustic" is a massive understatement. I put a large carpet underneath the tank to protect the lawn. Some solution splashed on to the carpet which immediately turned black and caught fire. This was at the end of the procedure and I won't be repeating it.

[Blackstuff]

Sounds like one of those classic situations where its best just to pay someone!

[FredB]

You did it the hard way. The steam bath is good, but all you need is one of the rusting compound —Ed Blackley sells them for both blueing and browning. After rusting with the appropriate salts you simply boil the barrel. I have always had good results with this method.
Fred

[waterford103]

I used to buy ready to use compound from HELSTON gunsmiths ,boiled up the bits in a stainless steel trough . As with everything preparation is everything .

[Dark Skies]

Sounds like one of those classic situations where its best just to pay someone!

But it's so satisfying when it all works out. I boiled up a batch for the barrel and cylinder of an old Pietta Colt Navy and it looked wonderful.