Overheating a barrel?

[contenderfan]

Ok I know this is gonna sound crazy but I know I read this somewhere before...Has anyone ever heard of a browning/blueing process that involves laying the barrel of a muzzleloader in a bed of coals until its glows a dull red?
Ive been doing a search on this but cant find anything about it. I know I read an online article about a gunmaker that does this process...but I just dont understand how this wouldnt ruin the barrel and cause a catastrophic failure. Just seems it would compromise the strength of the steel to me.

 

[contenderfan]

Just found the info...its called charcoal blueing. Still dont understand how the heat dont affect the strength of the barrel steel, looks like the barrel would blow up when you shoot it to me?
Anyone know more about why this dont weaken the barrel?

 

[Bill Hall]

In most cases, the only time heat will compromise the strength of steel is when the steel has been heat treated for a certain application. If the heat is hot enough, it will anneal the steel, causing it to become softer, therefore rendering the metal useless for the specific purpose. Gun barrels are not heat treated to begin with, therefore no annealing takes place when heat is applied.

That doesn't mean that too much heat will not cause damage to a barrel though, such as warping, shrinking, melting, etc. Obviously, charcoal bluing just doesn't get hot enough to do any harm to the barrel, or it wouldn't be in use.

I do alot of soldering on barrels, and some guys can even silver solder without doing any harm. I stay away from the latter, since I would probably do some harm. :surrender:

In certain applications, such as with aviation parts, grain orientation of the metal must be considered, and overheating a part can change that orientation. I just don't think gun barrels are grain structure specific, so it's not an issue here. Bill

 

[Zonie]

The barrels used for modern cartridge guns is a high alloy steel which undergoes special heat treatment to raise its strength to the levels needed for smokeless powder.
Charcoal bluing one of these modern barrels would indeed damage it making it dangerous to shoot.

The steel used to make muzzleloading barrels is a low carbon material that is not heat treated.

Heat and quenching will not harden it to make it stronger or weaken it if it is annealed.

Like the wrought iron used in the 18th century and the low carbon steels of the 19th century, charcoal bluing will not cause a problem for a muzzleloader.

 

[Bill Hall]

The barrels used for modern cartridge guns is a high alloy steel which undergoes special heat treatment to raise its strength to the levels needed for smokeless powder.

Well there's something I never knew. Thanks Zonie. Bill

 

[Dphar]

Ok I know this is gonna sound crazy but I know I read this somewhere before...Has anyone ever heard of a browning/blueing process that involves laying the barrel of a muzzleloader in a bed of coals until its glows a dull red?
Ive been doing a search on this but cant find anything about it. I know I read an online article about a gunmaker that does this process...but I just dont understand how this wouldnt ruin the barrel and cause a catastrophic failure. Just seems it would compromise the strength of the steel to me.

Its called charcoal bluing, but there is more to it than just laying the barrel on a bed of coals. This process was done to anneal skelp welded iron barrels before boring and rifling.
Charcoal blue was common in Colonial America, was used on many 19th century and early 20th century guns. Like S&W revolvers if I am properly informed...
But there were steps taken to control the atmosphere to reduce scaling etc.

Dan

 

[Dphar]

The barrels used for modern cartridge guns is a high alloy steel which undergoes special heat treatment to raise its strength to the levels needed for smokeless powder.
Charcoal bluing one of these modern barrels would indeed damage it making it dangerous to shoot.

The steel used to make muzzleloading barrels is a low carbon material that is not heat treated.

Heat and quenching will not harden it to make it stronger or weaken it if it is annealed.

Like the wrought iron used in the 18th century and the low carbon steels of the 19th century, charcoal bluing will not cause a problem for a muzzleloader.

I dunno I have shot some M-16, M-60 and 50 BMG barrels till they were very hot and seen other people do the same thing. For example running 100 rounds through a M2 50 caliber HB in one burst will heat the barrel to red. Shooting 100 round bursts was common practice for the Quad 50 on a FSB I used to frequent back in my "youth". Even in short bursts in sustained fire full auto barrels get very hot pretty fast. They did not blow at red heat or after cooling. Many were run though this cycle quite a few times actually. This is far above what charcoal bluing will produce which is basically a spring temper temperature.
But then moly steels have a high heat tolerance. Obviously this is one reason one of the 4150 variants is used by the military.

Dan

 

[Rifleman1776]

The steel used to make muzzleloading barrels is a low carbon material that is not heat treated

I've long been under the impression that many different kinds of barrels and steels were/are used by various manufacturers of ml barrels. And that would be the source of the never-ending debates on whose is best/worst, etc.
e.g. the Douglas barrel haters believe all their barrels will blow up because it is the 'wrong' kind of steel. BTW, how many Douglas barrels are out there in use? :wink:

 

[hanshi]

This is very interesting information. I'd like to charcoal blue a couple barrels I have but I know there's more to it than just putting them on coals. There is likely a good deal of knowledge and skill required to do it successfully.

 

[matt denison]

Charcoal blueing doesn't involve enough heat to turn the barrel red as the OP mentioned. - ! unless you screw it up ! (oops) You only want to turn the barrel blue which is about 600 - 650 degrees. Burrying it in charcoal heats it and keeps oxygen away at the same time so it doesn't slag up. The bore is also packed with charcoal to prevent oxydation (slaging) too. It is an art of sorts, best to practice on scrap first.

 

[contenderfan]

Thanks for all the info fellas. Im not planning on attempting the charcoal blueing...was just curious about why it didnt effect the steel in a negative way where strength is concerned.
Now I know... :thumbsup:

 

First the process require real charcoal, not the processed briquets you see today. The barrel is filled with powered charcoal. some people use a steel container, others use a pit. The barrel needs to be prepped, polished, cleaned and oil free, and then buried in the started charcoal with a coverage of three to four inches. This creates an air free chamber for the barrel, then it's allowed to burn itself out. The charcoal powder in the barrel doesn't burn, as it's packed tight to protect the rifling. The hardest part now a days is getting the real charcoal. I have only tried it on a four inch scrap of barrel, and I was quite pleased. I have a 52 and 3/8 inch .52 cal. custom profile barrel I want to try in the spring. Have to finish the build first, though.

Bill