word etymology

[TimB]

I was wondering if the term "Gun bluing", which refers to a layer of rust resisting oxidation on a gun barrel, was once a reference to the temper a gun barrel was brought to?

Which leads to another question, are the temper colors actually oxidation that would resist rusting?

[Frank Turley]

I doubt if they are related. There is a great 55 minute video "The Gunsmith of Williamsburg" featuring Wallace Gusler making a flintlock as it might have been done during the colonial period. The barrel is of wrought iron, a formed tube forge welded over a tapered mandrel. It took over 200 heats to get the job done. This was labor intensive. At a later time, the solid barrel was drilled and bored at water powered boring mills, no heat needed. In both instances, the barrels were of wrought iron of extremely low carbon content, so hardening and tempering was not an option. I understand that some contemporary barrels are made of medium carbon steel that is hardened and tempered, but I venture all that is done high tech and with pyrometer control...having nothing to do with blue oxidation.

I think that bluing and browning of barrels resists further rust to a small degree if the gun is cared for and kept indoors. However, "Rust never sleeps."

Turley Forge and Blacksmithing School

[Bentiron1946]

I have never seen a blue job resist rust to any great degree uless oiled. True bluing is done hot and not with this cold stuff sold in little bottles. When I was a wee little lad I would polish the gun parts till one could pop zits in the steel then it was on the the bluing vats. Boil and bubble, toil and trouble, first the degreasing vat, next I think was the bluing vat, then the neutralization vat and a warm light oil soak while everything was hot. If you wanted protection from rust get it Parkerized or black nickle plated.

Edited December 21, 2009 by Bentiron1946

[HWooldridge]

The first guns were likely filed bright and polished with emery. Turned out that bright and shiny attracted attention from both man and beast (a bad thing) and BP causes rust to develop even faster than normal so controlled rusting became the norm for finishes - which is called "browning". Someone then discovered that boiling a browned part for a period of time made it turn dark blue.

Some small parts such as screws were heat blued but barrels were not tempered. For the most part, barrels were always soft iron or steel until smokeless came along - made it easier to cut rifling in the bore. Even now, many barrels are the equivalent of 12L14, with 4140 only used on some weapons.

To answer your second question - heat bluing is quite thin and is only slightly better at resisting rust than bare steel. Better to let it rust and kill the chemical action then oil the part (which brings us back to browning).

Edited December 21, 2009 by HWooldridge