Case Coloring

shortgrass

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Modern alloy, chrome moly steels do not CCH well. Your basic, low carbon steels or cast iron are where CCH is used. I don't think that even Doug Turnbull will CCH a modern, centerfire rifle receiver,, not even a Mauser '98, which is made of low carbon steel. CCH is more than 'colors'. The colors are just a by product of the hardening process.
 

KyCarl

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I have a 1911 with a beautiful case hardened frame and I'm sure it's a high carbon steel
I'll message the guy who built it and find out what it's made of and who heat treated it?
It wasn't cheap I remember that!
 

J E Custom

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You have one or two options,
Take the advice from someone that does it (Shortgrass) and knows what a good job looks like, and knows how and what materials do best, Or take a chance on how it looks when it is done.

I have seen beautiful case hardening jobs, and ugly ones and worked on actions with both (Good and bad) and they even machined differently.

Good luck

J E CUSTOM
 

Edd

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Tulsa
You have one or two options,
Take the advice from someone that does it (Shortgrass) and knows what a good job looks like, and knows how and what materials do best, Or take a chance on how it looks when it is done.

I have seen beautiful case hardening jobs, and ugly ones and worked on actions with both (Good and bad) and they even machined differently.

Good luck

J E CUSTOM
There might be more options than that.

Do you know how Dakota gets the color on their Receivers?
 

shortgrass

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Chemical. No one (Turnbulls reason, mine,too) wants to except the liability of altering the heat treat of a centerfire rifle receiver. Handguns and shotgun receivers are something else. 8620 colors beautifully. And many black powder cartridge rifle replicas use this steel in their receivers. 8620 is 'predictable' in its CCH properties. I doubt Dakota would reveal their process or the steel used in their receivers.
 

J E Custom

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There might be more options than that.

Do you know how Dakota gets the color on their Receivers?


I sure don't, I just know that normally there are propitiatory procedures and materials that are a close guarded secret and I won't risk doing something that may not turn out or could damage the action if I don't have enough information to feel safe to proceed.

That is why I have only two options. Yes, if I know enough about all the important issues, and No if I don't. That's why I rely on the experts for some things.

I have done case hardening many years ago, and it is one of those Art forms as far as I am concerned and I personally would never attempt to do It myself on something as important as receiver because of my lack of experience.

Just me

J E CUSTOM
 

shortgrass

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Maybe Dakota use a steel that can be CCH. Like JE has said, proprietary information. When Colt brought back their SA Revolver, they had to run an extensive R&D program to CCH the frames like the original were. All of the men who had done the CCH on the originals were either retired or passed on. How many thousands of $$$ were spent? Only Colt knows. I know I spent a lot after taking the basic, week long NRA Summer Gunsmithing class, at Murry State in Tishomingo, to get the basics of CCH. It was just a place to start. A good heat treat oven, obtaining suitable media (different types of charcoal), building crucibles and the tools to handle them when they are "cherry red hot", building a quench tank, and then many, many hours of 'experimentation' to learn what worked and what didn't. That was for the original, charcoal packed CCH process. Evidently, there are some other processes that mimic case colors. Doug Turnbull has a bunch of that figured out, as he's one of the only I know of that can/will color 4140HT, 4140HT being the alloy steel used by many manufactures for their rifle receivers. But I don't think he will do a centerfire rifle receiver, from what I have been told. There are many other alloy steels that are lower in carbon content that CCH very nicely, like 8620 that I mentioned previously. 8620 being chrome .50%, nickel .55%, molybdenum .20% with a carbon content of .20% +-. Most steels in that .20% content seem to color nicely, and quenched at the proper temp produce a good, hard 'case' on the outside. Provided with the proper 'controls', temp of the part before quench, time held at that temp, the carbon bearing media that the part is 'packed' in, the temp of the quench, the steel itself, repeatable case hardness and colors can be reproduced from part to part. Then their is the warpage to contend with when going from high temps required for most heat treating processes (CCH included!) into the quench. Not done properly, the 'part' being CCH may warp enough that any additional 'parts', needed to complete the final assembly, may no longer 'fit'. It's just not as simple as it all appears to be. The placement and 'coverage' of a 'part' with case colors is completely at random, no 2 are alike.
 
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J E Custom

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There might be more options than that.

Do you know how Dakota gets the color on their Receivers?


After more thought, there may be one more possibility .
I would ask defiant to CCH one of there receivers for me and let them take the responsibility and not risk voiding there warranty.

There are many things that those of us that are afflicted with the LRH type of shooting would like to do, but some are more risky than others and should be considered before we act on our wants. I love the looks of a good CCH job and just because I am to conservative doesn't mean it can't be done, just that I wont try it on my on.

J E CUSTOM
 

Trickymissfit

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greenwood, IN
Modern alloy, chrome moly steels do not CCH well. Your basic, low carbon steels or cast iron are where CCH is used. I don't think that even Doug Turnbull will CCH a modern, centerfire rifle receiver,, not even a Mauser '98, which is made of low carbon steel. CCH is more than 'colors'. The colors are just a by product of the hardening process.

Listen to Shortgrass! With today's actions being made of 4**** chrome moly steels, and usually bought in a pretreat condition, your going to draw the heat treat back way too far to be safe. Yet there are a few high quality falling block actions (probably some others as well) being made from standard 8620 steel. You could probably get by here.
(assuming they didn't carburize it)
gary
 

Trickymissfit

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Chemical. No one (Turnbulls reason, mine,too) wants to except the liability of altering the heat treat of a centerfire rifle receiver. Handguns and shotgun receivers are something else. 8620 colors beautifully. And many black powder cartridge rifle replicas use this steel in their receivers. 8620 is 'predictable' in its CCH properties. I doubt Dakota would reveal their process or the steel used in their receivers.

reason folks like to machine 8620 is that you get 1020 quality without all the crap 1020 gives you. I bought 8620 by the flat bed truck load for a reason; it machines well and is very stable in the machine process. When making long cuts it rarely moves around on you, but on the downside; it's soft and will not harden on it's own. You can harden parts of it via the carburizing process, and then machine off what you don't want hardened.

Only serious chemical coloring I can readily think of is black oxide. I did a lot of black oxide, and it's a basic acid etch. Another process is Tin coating. This stuff is serious, and will probably wear forever. Down side is the color (for some of us anyway). There is another process that comes in a matte black, and it wears like Tin coating. What it actually is, I don't know as it's closely guarded. I really like NP3 chrome, and as I understand it, it can be done in colors.
gary
 

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