Model 59 and 39 slide coloration

[Slufstuff]

I have noticed an unusual number of S&W Model 59 and 39 blued slides that have turned a plum color over the years, ranging from a slight tint, to an overall plum finish. I was looking at a NIB Model 59 at the gunshow this weekend that was never fired, not out of the box much, etc. And it was almost an overall plum color. Slide only, the aluminum frame was still blue-black in color. Why is this so prevalent on the 59/39 pistols? Was there some flaw in the bluing process, or what? Appreciate any insight.

 

[Slufstuff]

I have noticed an unusual number of S&W Model 59 and 39 blued slides that have turned a plum color over the years, ranging from a slight tint, to an overall plum finish. I was looking at a NIB Model 59 at the gunshow this weekend that was never fired, not out of the box much, etc. And it was almost an overall plum color. Slide only, the aluminum frame was still blue-black in color. Why is this so prevalent on the 59/39 pistols? Was there some flaw in the bluing process, or what? Appreciate any insight.

 

[Mortech]

Its just the side effect of the bluing process S&W uses . My 39-2 , 469 are a nice kind of plum color while my 59 has stayed a pristine black , I think it has something to do how much they are exposed to the everyday elements , the former listed pistols were everyday used ones while the 59 was someones safe queen for a long period of time so I wouldn't conider it a flaw since a couple of my older german PPKs had turned plum colored also .

 

[oldrip57]

The copper Statue of Liberty is green, many old silver coins exhibit rainbow 'toning'. Metal, as it ages, changes color -- a chemical process. Simple as that. Guns are made of steel, a metal. Hence, they change color.
The less they are used, the more they change.