What happened to salt bath nitriding?

[762willdo]

Did it ever work, I have a guy that wants to sell me a new krieger barrel but he had it nitrided and I’m not sure about it…….

 

[jelenko]

From my experience, there isn't any downside as long as the process was done correctly.
Mixed reviews on whether there is longer barrel life.

Note: On AR barrels, the barrel extension often comes loose after the process.

 

[shortgrass]

Did it ever work, I have a guy that wants to sell me a new krieger barrel but he had it nitrided and I’m not sure about it…….

If it has been Melonite/Black Nitrided before it has been fit (threaded, chambered, headspaced & crowned) , you'll need a carbide reamer to cut through the hard surface. Nitride treatment before fitting would be completely counter productive.

 

[CharlieNC]

I obtained a prefit 6.5x47 barrel which was nitrided as purchased by Criterion. It provides first round hits on steel at 1200yd , comparable or better than the Bartlien it replaced. Cleans easily too.

 

[SteveOak]

Nitride treatment before fitting would be completely counter productive.

Why is that?

 

[Preacher]

Why is that?

To hard to work the hardened steel..

 

[SteveOak]

Why would you not fit the barrel before nitriding?

 

[shortgrass]

Why is that?

Besides needing a carbide reamer to cut the chamber, if you did use a carbide reamer the throat would be not treated, it would not be 'hard' . Many look at Black Nitride as a "finish", but the main point in my little mind is to increase accurate barrel life. If the throat is not nitrided, ,,,,,,,, well , make the mental deduction from there... Many people (including me!) still have barrels and some actions Melonite/Black Nitride treated, especially those chambered for the "barrel burners". In any case, if the Krieger barrel you have been offered has been fit to an action, and then Nitride Treated, it may need to be headspaced to your action. Not a problem if the barrel needs set back to achieve headspace. But certainly a problem (if you don't have a carbide reamer) if the chamber need cut deeper, but there it would leave you with a chamber throat that is not 'hard', like the rest of the barrel. Either way, a barrel that has been nitride treated is pretty much useless if it has not been fit, and dedicated to the action it was fit to, if it has been fit.

 

[butchlambert]

Nitride before chambering is stupid. Nitride is basically a case hardening to greatly enhance barrel life. Chambering afterward would eliminate the advantage. The best shooting and by far the longest lasting BR barrel that I've owned was a Kreiger that was melonite treated. The only ones that have had a poor experience was the person did not know that you had to be sure all the salts were thoroughly cleaned after treatment. I leave mine under water for a couple days and then run a couple patches through it with JB. No break in is required.

 

[SteveOak]

I asked the question poorly.

Why would you not fit the barrel first and then have it melonited?

 

[butchlambert]

I asked the question poorly.

Why would you not fit the barrel first and then have it melonited?

I thought I answered you.

 

[SteveOak]

Nitride before chambering is stupid. Nitride is basically a case hardening to greatly enhance barrel life. Chambering afterward would eliminate the advantage.

Not that I can tell. LOL

Why would you not fit the barrel first and then have it melonited?

 

[Edd]

This is copied from the Krieger Website.

• Do you recommend Salt Bath Nitriding?

No. There have been many praises of this surface hardening treatment applied to rifle barrels in relation to extended barrel life, easier cleaning, non existent copper fouling. However there are some concerns that must be understood if you move forward with this.
The temperature that the steel is brought up to during this process is within the range that can remove the temper from the steel if not properly finished potentially causing the steel to become dangerous and not contain the pressures your cartridge will produce. Any heat treating process done after the rifling process can lead to bore and groove dimensions and uniformity being changed.
Also, the salt bath nitriding process produces a very hard surface finish. If the barrel is not broken in prior to this process being done, it will never properly break in. If the barrel is broken in there could be traces of copper left in the bore (even in the pores of the steel) and it will react with the nitriding process in the form of pits or corrosion in the barrel where it reacted to the copper.
The person or company you choose to do this operation must be aware of these items and should assume responsibility for what happens to your barrel as all of these operations and procedures are out of the control of Krieger Barrels, Inc. For these reasons, we do not recommend salt bath nitriding.

 

[Dave M.]

Not that I can tell. LOL

Why would you not fit the barrel first and then have it melonited?

The answer is that you should do it that way, that is the proper way to do it.

 

[butchlambert]

Not that I can tell. LOL

Why would you not fit the barrel first and then have it melonited?

Young feller, you have a problem with reading comprehension! There is no reason at all to mess with the chamber after melonite! Know do you understand what I am posting?

 

[butchlambert]

This is copied from the Krieger Website.

• Do you recommend Salt Bath Nitriding?

No. There have been many praises of this surface hardening treatment applied to rifle barrels in relation to extended barrel life, easier cleaning, non existent copper fouling. However there are some concerns that must be understood if you move forward with this.
The temperature that the steel is brought up to during this process is within the range that can remove the temper from the steel if not properly finished potentially causing the steel to become dangerous and not contain the pressures your cartridge will produce. Any heat treating process done after the rifling process can lead to bore and groove dimensions and uniformity being changed.
Also, the salt bath nitriding process produces a very hard surface finish. If the barrel is not broken in prior to this process being done, it will never properly break in. If the barrel is broken in there could be traces of copper left in the bore (even in the pores of the steel) and it will react with the nitriding process in the form of pits or corrosion in the barrel where it reacted to the copper.
The person or company you choose to do this operation must be aware of these items and should assume responsibility for what happens to your barrel as all of these operations and procedures are out of the control of Krieger Barrels, Inc. For these reasons, we do not recommend salt bath nitriding.

Edd, I understand, because they have no control over the treating firm or the customer. The only barrel break in that is needed is a light lapping of the throat to eliminate fluff from reaming. A quality barrel has been lapped at the barrel company. Your copper in a new barrel is the result of machining fluff in the throat.

 

[swd]

Why would you not fit the barrel before nitriding?

Yep, that’s the correct way to do it.

 

[angus]

I’ve just rebarreled my .204 ruger for the third time with a Krieger that I had melonited. My first .204 barrel needed replacing after approximately 2000 rounds. The second barrel was melonited and was replaced after approximately 4000 rounds. I fire 15 to twenty rounds and clean THOROUGHLY prior to sending off for melonite.

 

[FNSafari]

after chambering and fitting how much dimensional change does the nitriding add to the barrel?

 

[John11-87]

In my experience, melonite/nitride, QPQ parts are made with the expectation of a .0001-.0004 (per side) buildup. Hard black anodized on Aluminum parts is roughly .0008 per side, clear hard anodize is .0035 per side.

John