[ejohne]

I saw a Model 42 Winchester shotgun from the 1930's today. The blueing on the front half (it's a takedown) was a deep dark blue like other Winchester's I have seen of its vintage. However, the blueing of the receiver was lighter and had a reddish tint. At first glance, I thought it was wear, but on closer inspection, the blueing was uniform, just not as deep and with a reddish tint. Is this a normal process that occurs with Winchesters of this vintage? Thanks!

[Freightman]

This is called "Plum" and is caused by a high nickle content in the metal.
I have a Lugar that has did this nothing wrong just old.

[ejohne]

Ah, I found this quote in alt.rec.guns:
"One sometimes sees blued steel that has developed a reddish cast. That occurs when there is partial reoxidation of the reduced iron oxide (not rusting of the base metal, just a change in the chemistry of the bluing)."

Would the receiver and barrel be of different metals such that one would oxidize and not the other?

[Freightman]

That is true!