Question about color case hardening high pressure barrels

[Evanguy]

Im wondering about color case hardening high pressure rifle barrels.

Ive been doing some work machining for Oskar (https://ww w.oldguns.ca/restoration-services.html)

And for this next job i was thinking of getting some parts CCH. I have 2 remington no6 falling blocks to get done. Then i started thinking it would be cool if i got my 460 weatherby barrel CCH.

Im not sure where the barrel is 4140 if its a good idea or cant be done.

So my question is can you CCH high pressure barrels with out any ill effect?

Here is the rifle id like to do it to

And here is a link to the barrel used https://www.tradeexcanada.com/content/mauser-m98-barrels-zastava-458-win-mag

Here are the front and rear sights im going to use.
https://www.newenglandcustomgun.com/proddetail.php?prod=4685
https://www.newenglandcustomgun.com/proddetail.php?prod=4249

 

[guntech]

Ive been doing some work machining for Oskar...So my question is can you CCH high pressure barrels with out any ill effect?

Why in the world would you not ask Oskar?

I saw the colour cased hardening being done back in 1966. It involved heating the metal red hot and quenching it (swirling it around) in a pot of very hot chemicals including cyanide. I would never do that to a barrel... and it would require a very large pot for quenching.

 

[Evanguy]

Yeah i will ask him. Hes a call only type guy and im at work right now and have been thinking about it this morning. Well the barrel part annway.

Yeag thats why i though it may be a bad idea but if it can be tempered after without ruining the color then it may still be ok to use as a barrel.

Im not sure. I will talk to him about it. But was also looking to get opinions in the mean time.

 

[Snider shooter]

Ive been doing some work machining for Oskar...So my question is can you CCH high pressure barrels with out any ill effect?

Why in the world would you not ask Oskar?

I saw the colour cased hardening being done back in 1966. It involved heating the metal red hot and quenching it (swirling it around) in a pot of very hot chemicals including cyanide. I would never do that to a barrel... and it would require a very large pot for quenching.

Oskar uses bone charcoal. Does an amazing job.

 

[trevj]

Ive been doing some work machining for Oskar...So my question is can you CCH high pressure barrels with out any ill effect?

Why in the world would you not ask Oskar?

I saw the colour cased hardening being done back in 1966. It involved heating the metal red hot and quenching it (swirling it around) in a pot of very hot chemicals including cyanide. I would never do that to a barrel... and it would require a very large pot for quenching.

Cyanide is a pretty easy source of Carbon to absorb in to the surface of the part being hardened, but there are lots of other sources that will work, without the serious health issues that cyanide hardening poses.

The only barrels I have seen case hardened, have been pistol barrels (See Turnbull Restorations site) I know that it is possible to pull up pretty good case colors at lower than through-hardening temperatures, but I would be pretty leery of cooking a barrel and quenching it, with any expectations of accuracy afterwards.

Consider, that almost all the heat treatment of barrels is related to stabilizing them or releasing stresses, while quenching a color case part is pretty much the complete opposite of that, you quench the part in a bucket of water and assorted chemicals, with a bunch of air roiling the whole thing up like it's at a boil.

I'd definitely ask the source. Worst case is a crooked good looking barrel. Well I suppose, worst case would be a blown up barrel...but...

 

[ShawnC6]

I wouldn’t based on the metallurgy of it.

First concern would be the wrong heat treat for the pressure.

Second concern would be distortion.

 

[Leeper]

In my experience, absolutely not. This is not to say it might not be possible to colour it by some means but colour case hardening just doesn't work on 4140. I have seen case hardened 4140 actions which cracked while sitting on the workbench.

 

[Scarheart]

I work with Oskar a lot. I can tell you this wouldn't be a great idea. Besides what others have said about the functional metallurgy aspect of it modern metals are to uniform and that combined with the alloys in them make not as pretty colors and patterns as older metals.
All the barrel we work on are treated in a different way. Blueing etc. Only the receivers and other bits are CCH.

 

[Evanguy]

Ok thanks, thats why i made this thread. Ill just get him to blue it for me then.

I just thought the colours would look good on the barrel and it needs to be protected anyway.

I thought that maybe one could temper the barrel after to what ever hardness you wanted (~35 rc)But also realize it full of carbon so not sure how if it would work like mild steel.

If it was low pressure i wouldnt have been so worried.

Pre-war mauser receivers were case hardened mild steel, But where the barrel is 4140 it kinda throws a wrench in the mix

blued it is.

 

[Blastattack]

Color case hardening generally does not look good on barrels. It really only looks good on the receiver, with all other parts being blued. It also does not look good on anything modern. I saw a P7M13 done in CCH and it looks hideous.