Hello- I have a P7M8 I bought new around 2004. I remember the police turn-ins that had the slides refinished to a plum color, and now it seems like the slide on mine is going plum. Is that normal?

The frame is maintaining its factory color. Is this a result of incorrect chemicals for cleaning it? I would think the frame would go plum too in that case.

Had a great time with it at the range yesterday.

Thanks

Dan

The plum coloring is normal. Here's what I'd found and posted in this somewhat recent thread:

https://sigforum.com/eve/forums...100075444#8100075444

This is the best explanation I've ever found when I was looking into P7s (I copy/pasted several posts from user "lowegan" from THIS thread on the Ruger forums):

jmichael1982, Plum color on Rugerframes, loading gates and cylindersis quite common with older guns. It's actually a defect but many people ... especially collectors go nuts over defective bluing jobs.
Here's the skinny ... bluing salts are added to pure water to form a "super saturated solution". When mixed to the proper proportions, it goes to a low boil at 292 deg F, which is the ideal temperature for hot bluing tanks. Water boils at 212 deg F so you have to keep adding water or the solution will get too strong. If the solution is not carefully controlled where either the temperature gets too high or too much water boils off, the gun will come out of the tanks with a plum color.
Further, Ruger uses molybdenum in their frames, cylinders, and loading gate alloys. This strengthens the metal but has a nasty side affect ... in time, a nice bluing job will turn plum colored. Some times it takes several years for the plum color to show up ... sometimes it never does show up.
So ... a combination of the two above conditions ... older RugerSAs could come right out of the box with a plum color or may turn plum in a few years .... either way, it's a defect in the bluing process that can be avoided. Ruger now uses an additive in their bluing tanks that prevent plum coloring. Brownell's sells it as "S" additive. BTW, you rarely see plum barrels because they are a different steel alloy.


Quiet 1, Thanks, I'll try to live up to "wisdom".
FYI, In my shop, I had a good set of Brownell's bluing tanks and using Brownell's Oxinate 7 salts (the industry standard), I learned many things the hard way. For example ... if you blued a Winchester Mod 94 frame without the "S" additive, it will come out of the tanks about as red as a stop sign. With the "S" additive, they turn out nice and blue (actually black). Any other gun with a cast frame, such as a break barrelshotgun, will do the same thing.
My first 357 Mag Ruger Blackhawkwas a 1976 vintage Liberty model. A few years after I bought it, the frameand loading gate started turning plum. I carried this gun many times in a holster when I hunted or just went for a horse ride in the Colorado Rockies. After a few years, much of the bluing wore off and there was even more plumb color on the frameand loading gate. I decided to reblue it. A few years after rebluing it, the frame started turning plum again only this time it also had defined plum streaks, which is also common with the factory bluing. I gave it an acid bath to remove all the bluing ... plum color and all. This time I used the "S" additive and it turned out great. From that point on ... all the Rugers got blued using the "S" additive and I never had one turn plum. I still own the Liberty BH ... it's been over 30 years since I reblued it and it's still blacker than a sinister's heart.

No, I don't think it makes any difference. As explained to me by a metallurgest, once a gun has been blued, the surface of the metal(about .0001" deep) will continue its ionization process for many years. With most guns, this means the surface finish will look better with age, assuming the bluing has not worn off. With some Rugers, it means molybdenum will continue to react and turn plum. Those gunsshipped plum collored due to poor bluing tank control seem to get more and more plum colored as they age.
Ale-8(1), Back in the 70's, people would get rid of plum colored Rugers and they were hard to sell so many of them were reblued. Not to worry ... I still have several OMs and a couple NMs with some plum color. Personally I don't care for plum but because they now are considered more valuable ... I won't mollest them. I do think it is very strange when people are willing to pay extra for a defect.

Yep normal. My p228's end of muzzle and hammers look like that. I think it gives it character.

I've seen it happen with several manufacturer's firearms. My P7M8, purchased new back in the '80s, has not turned plum. But if it did, it would not cause me concern. I've probably seen more Rugers and SIG P210s starting to turn plumb than anything else. Had the opportunity to purchase a new limited edition Colt years ago. The slide had already started turning plumb. It happens.

I see it most commonly on P228s. Wonder why.

quote:

Originally posted by 12131:
I see it most commonly on P228s. Wonder why.

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I had thought it was because of the weld making a difference in hardness between slide and chin. So my guess is that some welders were running hotter than others. But that doesn't explain that only some hammers turn plum. My hammer is turning plum but only the portion that see's daylight, and chin has turned plum, a KE.

No, it is quietly rusting away to Oblivion. I'll do you a favor and take it off your hands for $600.

[QUOTE]Originally posted by Rolan_Kraps:
No, it is quietly rusting away to Oblivion. I'll do you a favor and take it off your hands for $600.[/QUOTE
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That would just piss off the rust fairies.

You know, I think it did corrode away to oblivion. I might just testify to that some day.

Winchesters with nickel steel barrels turn plum as well.