salt bath nitride and velocity

[Oldcappj7]

I used H&M on all four of mine. I cleaned the daylights out of them before nitriding and upon receiving them back. As Rich said there was a fair amount of brown that took some cleaning to eliminate.

Jace

 

[Pdvdh]

I don't believe salt bath intruding, done properly, damages a rifle barrel. There are companies selling pre-nitrided AR15 barrels, that continue with the practice.
I think the problems are bad process technique. Or the barrels are already heat cracked when sent in. Again, bad treatment technique. The nitriding company has to perform their treatment process correctly, on a qualifying barrel.
Which leaves us with... Who's good at it and who's less than good?

 

[Smokinghole]

I don't believe salt bath intruding, done properly, damages a rifle barrel. There are companies selling pre-nitrided AR15 barrels, that continue with the practice.
I think the problems are bad process technique. Or the barrels are already heat cracked when sent in. Again, bad treatment technique. The nitriding company has to perform their treatment process correctly, on a qualifying barrel.
Which leaves us with... Who's good at it and who's less than good?

I have three nitrided barrels from AR15Performance and they're all awesomely accurate barrels. One 6.5 BRX one 6.5Grendel, and a 3R 5.56 barrel. His barrels are 4150 no 4140 if that matters much. Same as the chromoly from Walther. It doesn't seem 4150 I'd a common match barrel alloy.

 

[elkaholic]

I don't believe salt bath intruding, done properly, damages a rifle barrel. There are companies selling pre-nitrided AR15 barrels, that continue with the practice.
I think the problems are bad process technique. Or the barrels are already heat cracked when sent in. Again, bad treatment technique. The nitriding company has to perform their treatment process correctly, on a qualifying barrel.
Which leaves us with... Who's good at it and who's less than good?[/QUOTE

Which is why I said you have to know the record of who is doing it! I assumed, from what I was told, that meant temperature, but likely otter things too. I don't know the answers to those questions, but for whatever reason, there are very mixed results!

 

[Buck Buster]

Thanks to : Elkaholic & Prieto9000 for your replies ; I assume that this is done mostly by competitive shooters, and is there always a gain when this is done?; ( smaller groups )? Thanks again for your answers they are appreciated.

 

[Pdvdh]

Another thing that I think is missed is complete cleaning of the bore after nitriding. There is some very persistent rust like crud remaning that took me considerable effort to remove!

Agree with the necessity of proper cleaning of the crud from the bore, following nitride barrel treatment - BEFORE firing bullets down the bore. Don't bother with any nylon bore brush. Use a bronze brush.
This link should take you to the process I used to clean one of my nitrided barrels, prior to firing any bullets down the nitride treated bore. Photos included to show the grit that's removed from the bore during this post-nitride treatment cleaning. See my Post #63.
https://www.longrangehunting.com/threads/the-338-rogue.168245/page-5#post-1206467

Other knowledgeable sources agree that the bores must be thoroughly cleaned following nitride treatment.

Another tidbit is Benchmark barrels has been happy with their nitrided barrel experiences, last I read about their comments and experience. They lap the throat after chambering the barrel. Fire a test round or two to confirm the assembled rifle is functioning properly. Clean the bore, and send it in for salt bath nitride treatment. Points being 1) no barrel breakin with 30 rounds fired down the bore prior to nitride treatment so no risk of heat checking the throat, and 2) they aren't reporting problems - last I knew. Why would they continue with nitride treatment if they felt it was detrimental to the barrels they manufacture?

Almost all processes that have potential for good, can be screwed up leading to bad, if performed improperly or if the barrel prep (in this case, pre and post-treatment) is overlooked... Even surgery, solely intending to yield positive outcomes can go badly. Salt bath nitride treatment of barrels is similar; less based on my limited personal experience, but mostly based on all I've read about the pros and cons of the treatment process.

 

[Pdvdh]

Thanks to : Elkaholic & Prieto9000 for your replies ; I assume that this is done mostly by competitive shooters, and is there always a gain when this is done?; ( smaller groups )? Thanks again for your answers they are appreciated.

Have no idea about that, but I doubt it's mostly done by competitive shooters.

Beneficial reasons for salt bath nitride treatment of barrels are 1) extended bore life 2) corrosion protection of both the exterior and interior of the barrel 3) less bore fouling allowing more shots fired before cleaning cycles 4) and easier bore cleanup.

No one claims better precision, to my knowledge. The best precision-related claim is that properly done, precision should not be negatively affected. Some competitive shooters do nitride treat their bores to increase accurate bore life.

 

[Pdvdh]

Or an action for that matter. I'm pretty sure that 1,100 degrees is affecting the heat treating of the steel in a barrel or action to some degree.

Barrels are heated to 1000 - 1100F intentionally, in order to stress relieve the steel after button rifling. Barrel blank steel is also carefully heated prior to shipment to the barrel manufacturers, for a positive purpose.

Heating to high temps is beneficial. Even mandatory to produce a safe, useful barrel.

Again, an example of high heat being necessary in order to produce a quality result. Heat applied improperly (cutting torch), could no doubt damage a barrel.

We're back to finding and using companies that know how to do it right, employ sufficient QA/QC to ensure they do it right, and work at doing it correctly. And then there's the matter of who's responsible to ensure the barrel is suitable for nitride treatment (isn't fire cracked in the throat), is properly cleaned prior to treatment, and is properly cleaned after treatment. If this is too complicated, then maybe avoid the process on your personal barrels. Is it really worth it? That's where this thread is leaning. It all depends... primarily on the opinion of the guy that owns the barrel and has to pay for the treatment process.

 

[desertcj]

Barrels are heated to 1000 - 1100F intentionally, in order to stress relieve the steel after button rifling. Barrel blank steel is also carefully heated prior to shipment to the barrel manufacturers, for a positive purpose.

Heating to high temps is beneficial. Even mandatory to produce a safe, useful barrel.

Again, an example of high heat being necessary in order to produce a quality result. Heat applied improperly (cutting torch), could no doubt damage a barrel.

We're back to finding and using companies that know how to do it right, employ sufficient QA/QC to ensure they do it right, and work at doing it correctly. And then there's the matter of who's responsible to ensure the barrel is suitable for nitride treatment (isn't fire cracked in the throat), is properly cleaned prior to treatment, and is properly cleaned after treatment. If this is too complicated, then maybe avoid the process on your personal barrels. Is it really worth it? That's where this thread is leaning. It all depends... primarily on the opinion of the guy that owns the barrel and has to pay for the treatment process.

Yes, I understand that. But the heat is followed by quenching resulting in heat treated steel. Looks like the tempering temp for 4150 steel is 400-1200 degrees. So the hardness of the steel could be affected depending on a lot of things. Your right though. The company doing the nitriding better know what they are doing....

 

[elkaholic]

Thanks to : Elkaholic & Prieto9000 for your replies ; I assume that this is done mostly by competitive shooters, and is there always a gain when this is done?; ( smaller groups )? Thanks again for your answers they are appreciated.

I'm not sure competive shooters use them more? I wouldn't be too surprised if they didn't because they take pains to make sure they don't mess up a good barrel and tend not to be risk takers as often as dummies like me! That would be a good poll topic for benchrest.
com though.

 

[tbrice23]

A couple of years ago I asked an older fellow competitor at a 600yd BR comp about it he said " If you want to mess up a good barrel have it nitrided".
He was do adamant about it I didn't even ask anything else.

 

[Buck Buster]

Thanks to: phorwath, Elkaholic, tbrice23; Thank you for your replies, I understand now. May 2018 be your best year ever.