Blue turning purple?

[Guest]

A friend tasked me with cleaning up a rifle he picked up at a garage sale. (He told his wife that's what she gets for making him go...a new rifle came home for a steal!) Anyway, it's a 25-06 Vanguard that appears to have been a sporter or a deluxe (I'm thinking deluxe that's just badly scuffed up and in need of some love). The barrel and bolt shroud are nice, shiny black. The action and bolt handle and scope (Leupold Vari-X II, I believe) have turned plum colored, and markedly so. I've seen this in some other old rifles, but never had a firm grasp on what causes an otherwise blued rifle to turn purple. I'm assuming it's some sort of chemical reaction to a solvent or something? Anybody have an explanation?

 

[pre6422hornet]

Dub,

I have a tang safety Ruger M77 that the reciever is a plum color, yet the bottom metal and barrel are a nice deep blue... Not sure when it happened or if it was there from the start. I have owned it since 1995, and my Great Uncle before me.

Interesting.... I am looking forward to the others with more experience to chime in.

 

[RiverRider]

I have a Winchester Model 12 that belonged to my grandfather and my great uncle (who was my grandfather's eldest brother-in-law and father surrogate) before him. It was made in 1936. I remember this gun being around from the time I was four years old when Uncle Ernst sold it to my grandfather for $50. The barrel and magazine tube were plum-colored then. I always figured the plum color was a transition color on the way to brown. It does still look plum to me though.

 

[elkeater2]

Nickel content of the alloy will cause this sometimes, or silica in the casting or molding processes. Silica should be cleaned off, but Ruger wasn't totally thorough in the early years. It is an aging process and not the result of cleaners or chemicals applied recently most likely. Some collectors value the 'plum' color - maybe because it verifies age and is difficult to fake.

 

[Guest]

I wonder if the silica would also produce the same effect on "blued" aluminum? I have a set of aluminum rings (off-brand, no-name) on my Win94 that were installed as a bargain setup with the $50 4x32 scope when I bought the rifle back in about 1984-ish. Of course, a $50 scope then is like spending $150 or more now, in terms of where it was in the price heirarchy. It's bright and clear, too - still. But I digress. Would silica cause this? Or perhaps there is some nickel in the aluminum alloy? I know zip about metals, as you may can tell.

 

[elkeater2]

Um, I only posted what I learned after doing web research, and feeling confident I had found reliable information. There is a fair amount of "gun blue turned purple (or plum)" data on various forums.
EE2