Update: Decided it is not worth the risk of warping but THANKS for all the input.

I have acquired a Flatside Contender frame and am considering having it color case hardened. My first thought was Turnbull but they no longer do original Contenders only G-2 and Encores. What I would like to ask is does anyone have personal experience with any other smiths that color case harden? All recommendations or opinions appreciated.

For info Marty at Haus of Arms (who handles Turnbulls TC firearms) says that the reason Turnbull no longer does Original Contenders is that it warps the frame about 50% of the time. While I trust Marty & Turnbull, I have wanted a flatside Contender CCH for a LOOOONG Time LOL

Some smiths advertise lower temperature Color Case Hardening. Maybe I should just leave well enough alone. What do you all think?

Thanks for reading
Doug

The original color case hardening process involved 'packing ' a part made of low carbon steel in a container (crucible) containing carbon rich materials, such as bone charcoal, charred leather or wood charcoal or a combination of such materials. Then heating to a specified temp for a specified amount of time, and then quenching. It was for low carbon steels only . The intention being to leave a hard surface layer on the part. This method does not work well with medium carbon steels and many alloy steels. What S.A.E. number is the Contender frame made of? It is most likely a medium carbon alloy steel. The original CCH process works well with S.A.E.8620, or 1018-1030. Some Mauser actions will CCH nicely, others not so much. It takes a temp of 1333 deg. F before hardness begins to take place. Lower temps (1250-1285) may produce colors. But, that part will be going from above 1250F in the oven to air temp quenching medium, hence, the risk of warpage in the part. "Blocking" can be built to minimize warpage, but the steel still need to be known for carbon content and alloy. Any other method where about any steel can be colored is faux CCH (just produced case colors) without any hardening. I took a NRA SUMMER Gunsmithing class in 2004 to get the 'basics' of the process. And, as I already had (have) a nice digitally controlled heat treat oven. I experimented more afterwards. The S.A.E. make-up of the steel needs to be known. I won't otherwise, unless I know that the 'part' was originally CCH when it was made. Many times that 'blocking' has to be made (like for sidelock side plates) to maintain shape without warpage. Mauser actions need 'blocking'. Best the part go through an anneal cycle before CCH and quench. Simple parts, like Sunny Hill floor plates, don't need 'blocked'. (low carbon steel). What I know about CCH would most likely fit in a thimble! I have experimented with my own 'parts' and researched extensively. I remember reading that when Colt decided to bring the SAA back into production they had to run an extensive R&D program so the frames could be CCH. I know nothing about the modern process where modern, medium carbon, alloy steels are "colored". I don't remember what year or issue numbers, but The Double Gun Journal ran a series of articles (written by Oscar L. Gaddy) about the CCH process (the original process intended to case harden low carbon steel or cast iron).

When I worked there (Turnbull) a long time ago, temp was 1430F. Quench was heated to 90F.

No blocking was done though his father who actually started the process had used it prior.

Some warpage occured,,we bent it back.
Win L/Actions would close up sometimes and a big steel wedge & hammer was used to open them back up.
Lock plates would warp slightly, but they responded well to a lead hammer.
Some times the Parker trigger plate would crack at the front where it is very thin to begin with. Extra thin after a re-polish.
All in all not a lot of problems with warpage though.

Then slightly lower temp was used to color but not harden, or harden as much if that makes sense.
No warpage probl.

Colors came out nice but wore off easily. SOmetimes during reassembly the edges were gone already.

There were drastic failures of a few C/C actions. Those were new mfg actions that people wanted C/C.
Obviously the metal was of modern alloy, not the low carbon steel of the 'old days'.
A work around ws found to be able to do the Rugers w/o any problems. But some of the other modern mfg guns were a no go. Too much of a chance of damaging the part.

That was then.

Likely things have changed and changed a lot. But being the business that it is where you fire up someone's Purdey or one-of Winchester to 1400+ degrees and then dump it into some warm water to make it show circus colors,,you can be very sure the operator is well aware of what works and what doesn't.

Decided it is not worth the risk of warping but THANKS for all the input.