Case hardened vs other steels

[Jethro "Black Jack" Harris]

Howdy, pards,
Is there any structural difference between case hardened steel and blued or stainless? Is it stronger, can it take a bigger load, or is it just purty to look at?

I just got a .44 Remmie with a case hardened frame and a 5 1/2 in. barrel. I wanna know what kind of load it would take and what kind of ammo I could use if I get a conversion cylinder for it.

Thanks fer all the help an' advice!

Jethro

[St. George]

Back when they used iron for the primary material of frames - case-hardening made those frames stronger and less prone to wear and stretching.

It's a surface hardening process done with heat - the color is merely a by-product.

Today - metallurgy has improved and steel is the primary material in use - a metal far harder than iron.

Colt and USFA both color case-harden their frames, since it's expected on that classic revolver - and it's a 'true' case-hardening - unlike the 'finish' seen on many of the clones and imports.

Incidentally - Remington never case-hardened their frames originally - it's a modern marketing gimmick that makes for an attractive finish.

As to your real question - case-hardened frames don't give you a 'magnum' capability - so use factory specifications for your shooting, and you'll be fine.

Vaya,

Scouts Out!

[Jethro "Black Jack" Harris]

Thanks, pard. I dint really think it mattered and I didn't choose the gun on that basis, but when I think of a question I gotta ask it or it festers...know what I mean?

Still wanna find out about ammo for a conversion cylinder. Any advice there?

J"BJ"H

[Flint]

Black Hills ammo for the R&D and Kirst cylinders is recommended.  It is made for CAS shooting.  Since 45 Colt shouldn't be loaded above the "factory" level to begin with, it is safe with lead bullets and 850fps or less velovity.   The Remington cylinder walls are very thin, and even with the 4140 or 4150 steel, aren't suitable for heavy over-the-book loads.  Neither are the softer parts of the Italian gun like the barrel.

Even the Ruger New Vaquero is not recommended for the "Ruger only" loads in the manuals....

Color case is a very thin skin, and helped prevent dings and scratches in the old Iron framed guns.

[Steel Horse Bailey]

Like others have said, it's a surface treatment.  Case Hardening (and Buck knives, for instance are case hardened - just not "color cased") will harden and form a "crust" of between .005" & .010" on the surface.  The color is an offshoot of some of the materials used in the hardening process. 

The Buck (and other knives) are a similar process, but without the colored effects, but that's how many internal gun parts can be ruined by too much filing/stoning that works 'thru the "crust" and into the softer metal beneath.  Same thing with the knives - especially if sharpened with power tools.  Then, both the heat AND depth of sharpening can ruin the blade or part.

[Driftwood Johnson]

Howdy

Case Hardening was not just for iron. Colt stopped using malleable iron for their frames and cylinders around 1883 and began using low/medium carbon steels. These were relatively soft steels, but they had plenty of strength for the Black Powder loads of the day. Modern heat treatable steels had not been developed yet. In order to provide wear resistance for the relatively soft iron or steel of the frames, the age old technique of case hardening was used. Heating the frames in a furnace surrounded by carbon bearing materials infused extra carbon into the surface of the steel, basically producing a thin layer of hard, high carbon steel. This increased the wear resistance of the parts, but since it is a very thin layer, it did not significantly alter the strength of the parts. The name 'case hardening' comes from the very thin 'case' of hardened steel surrounding the more ductile steel inside.

Today gunmakers are routinely using stronger steels than were available in the 19th Century. Some manufacturers like Ruger heat treat their frames completely through the metal, resulting in a stronger frame than possible with traditional case hardening. Other manufacturers are still case hardening the old fashioned way, but in truth they do it for the marketability of the colors, not because case hardening is any better than modern heat treatment.

I cannot speak for Kirst, but R&D makes their Remmie cylinders from modern 4140 heat treatable steel. They recommend "Cowboy Ammunition" for their cylinders, but in fact they are proofed for any SAAMI spec 45 Colt ammunition. You have not mentioned which brand of Remmie you bought, but as long as it has a steel frame, the frame will stand up to the pounding of recoil of any SAAMI spec 45 Colt ammo. Do not buy the high powered stuff put out by a few manufactuers for stronger guns, like 'original model' Vaqueros and Blackhawks.

If you stay with commercial 'Cowboy' loads, you will be fine.

[Jethro "Black Jack" Harris]

The Remmie I bought is Pietta. I wanted the 5 1/2 inch barrel, the case hardening was 2ndary and I just wanted to find out about it. That's what I love about this forum...ask a question and you'll learn tons of really interesting stuff. I also collect knives so I was interested in SH Bailey's info on the Buck knife. Now I know why the knife dealer said I should never let my Buck's get dull cuz I wouldn't be able to sharpen them! I usta buy machined parts, mostly aluminum, brass, and nickel, so I'm familiar with heat treating, for nickel anyway, but not so much for steel.

Haven't made up my mind yet about the conversion, but I do appreciate all the advice I'm getting!

Jethro

[Steel Horse Bailey]

The Remmie I bought is Pietta. I wanted the 5 1/2 inch barrel, the case hardening was 2ndary and I just wanted to find out about it. That's what I love about this forum...ask a question and you'll learn tons of really interesting stuff. I also collect knives so I was interested in SH Bailey's info on the Buck knife. Now I know why the knife dealer said I should never let my Buck's get dull cuz I wouldn't be able to sharpen them! I usta buy machined parts, mostly aluminum, brass, and nickel, so I'm familiar with heat treating, for nickel anyway, but not so much for steel.

Haven't made up my mind yet about the conversion, but I do appreciate all the advice I'm getting!

Jethro

Those Bucks are TOUGH!   They're hardened to about 55-65 Rockwell!  That's one of the hardest in the industry.  Since they are SO hard, they keep an edge, but are hard to sharpen again, especially if sharpened like conventional knives - they need much more angle than most knives.  I've seen some Bucks sharpened so much that the blade is only half as wide as it started - ESPECIALLY if sharpened regularly on a belt sander.  There, the Buck is actually relatively soft.  I don't remember exactly, but I think you're supposed to use about a 40-45 degree angle on them!  I don't know how long that'll last, however.  Buck knives aren't USA made anymore, if I understand right. 


SORRY!  I didn't mean to turn this into a Buck knife thread!

However, it proves the same about the gun parts - too much wear or stoning/filing and you'll cut right 'thru the hardened part into the softer steel beneath.

[Jethro "Black Jack" Harris]

Steel - me neither! But any hombre who has a holster on his belt otta have a nice scabbard too. I prefer Spanish stell. MolyVanadium, 58+ Rockwell, elk horn handle, red elk sheath...man, it don't get no better'n' that...

As for my Remmie...Cabela's offers bulk .45 LC Cowboy in 200 and 250 grain. Would either of those work for a conversion cylinder?

Don't wanna try thet thar smokeless stuff! It's fer dudes and bushwackers!

J "BJ" Harris

[Steel Horse Bailey]

Steel - me neither! But any hombre who has a holster on his belt otta have a nice scabbard too. I prefer Spanish stell. MolyVanadium, 58+ Rockwell, elk horn handle, red elk sheath...man, it don't get no better'n' that...

As for my Remmie...Cabela's offers bulk .45 LC Cowboy in 200 and 250 grain. Would either of those work for a conversion cylinder?

Don't wanna try thet thar smokeless stuff! It's fer dudes and bushwackers!

J "BJ" Harris

Yep - either will do fine.  The original 45 Colt load was a 255 gr. pill, so pick yer poison.

[Mako]

...Case Hardening was not just for iron...Today gunmakers are routinely using stronger steels than were available in the 19th Century. Some manufacturers like Ruger heat treat their frames completely through the metal, resulting in a stronger frame than possible with traditional case hardening...

Driftwood,
It actually depends on the steel.  Some steels such as 8620 which is a nickel, chromium, molybdenum alloy are routinely case hardened. It is a medium hardenability "carburizng steel" and it is almost always case hardened.  It was used extensively by the government arsenals to produce M-1 and M-14 receivers.  Case hardening temperatures are very high and the core of the 8620 will harden to a Rockwell 20-35 C range which is still relatively soft as far as heat treated carbon steels go and have a hard case of Rc 60-65 with a depth of up to .02 inches. You get a very tough core and a harder surface than you can with most through hardening steels at usable yield strengths.

You can't case harden steels such as 4140 because they will harden all of the way through and be "too hard. "  Since case hardening isn't subsequently tempered you will have a brittle piece of material.  If you tried to draw the hardness of the core then you would destroy the hardness of the case and any cosmetic coloration in the process.

I  mentioned 8620 because I am familiar with it, but there are quite a few alloys that are case hardened on a regular basis. 8620 still used today by several specialty manufacturers of big bore rifles because it produces  tremendously tough receivers with hard bearing surfaces.  It is also used for shafts, splines, bearings, gears and other applications requiring hard surfaces with high tensile strength and ultimate yield strengths.

I'm not trying to be contrary, but we many times talk about primitive metallurgy and processes when in reality they have and still produce the multiple properties that are needed in machines such as firearms.  For instance in a pistol we need a tough yet hard material.  This is usually mutually exclusive when you consider a through hardened steel, but is very attainable with case hardening.  The problem with most 19th century steels and iron was the impurities and non-homogeneity of the alloy creating weak spots and stress raisers.  When the Bessemer process converters came into use steel quickly became much "cleaner" and metallurgist had the ability to create controlled alloys with other metallic elements.  Considering the raw materials they had to work with we had some really creative inventions produced which you and I still use today.

Regards,
Mako