Barrel Nitriding Results

[kennyg]

I am considering nitriding a barrel on an upcoming build. The barrel is a 7 SAUM Brux. I was just wondering if any of you had tried this and if so what the results were, positive or negative. Specific questions I have are:

Velocity increase?

Barrel life increase?

Accuracy loss?

I am just not sure if I want to do this to a 450 dollar barrel. However the increased barrel life is appealing. I am most concerned about losing accuracy. I have listened to the video report that was on here about MMI and the guy that had shot 5000+ rounds in competition. Any help you can give me would be appreciated!

 

[Bob3700]

In our shooting group we have had four bbls treated. They range from a 308 Palma, 6.5x284, 6XC, and a 7mm WSSM.

All bbls have been very accurate (they are all on 600 & 1000 yd rifles) and easy to clean. We are keeping track of the throat wear with a Hawkeye.

So far, the treatment is all they claim it is.

Bob

 

[762willdo]

I have a 6dasher and a AR-10 (.308) barrel both nitrided and they are extremely accurate barrels, the only thing i would say is they seemed (to me) to take a little longer to "settle down" the dasher barrel took about 80 rds to optimize its performance and the ar-10 barrel about 100 rds, other then that no issues.
i have not noticed any increase in velocity according to my records, and i have not had them long enough to comment on barrel life.

 

[kennyg]

Hey guys thanks for the responses so far. Did you all shoot them first? If so, how many rounds prior to nitriding?

 

[GrocMax]

Nitrate or case hardening is old school, what I wanna know is if DLC/Casidium works, that stuff is The Shizz for high load low lube apps.

 

[gme]

Here's a study by the South Korean Defense Department regarding pulsed plasma nitriding of small arms barrels, it's a different process than the salt bath method but worth the read.
http://www.riflebarrels.com/articles/barrel_life1.pdf
Gary Eliseo

 

[kennyg]

I will admit I don't think I understood all of that, but it was interesting.

 

[Robert]

Here's a study by the South Korean Defense Department regarding pulsed plasma nitriding of small arms barrels, it's a different process than the salt bath method but worth the read.
http://www.riflebarrels.com/articles/barrel_life1.pdf
Gary Eliseo

Morning, Gary.

Interesting...

DCPPN is a long know process. I just went to chapter 'Conclusions' #5° to see confirmation...

R.G.C

 

[LSHopper]

I was involved in a DARPA project to find a way to increase barrel life without loss of accuracy for the 338 Lapua magnum. Melonite or Hot salt bath nitriding was determined to increase barrel life from about 1400 rounds to about 2400 rounds. I will tell you that these barrels were allowed to get very hot during the round count intervals of testing. The one thing we noticed very soon was, that if there was a tool mark in the melonited barrel when it was new, it was there when it was worn out.

This is a very worthwhile process in terms of increased barrel life. You also have the added benefit of coloring stainless steal and making the metal almost corrosion proof. I do recommend breaking the barrel in before treating the barrel if there are any lateral tool marks in the throat or particularly rough spots in the length of the barrel. Just make sure the barrel is cleaned down to the steel before treatment.

Thanks,

Lance

 

[kennyg]

Lance,

Did you experience any loss of accuracy in these barrels? I have heard people say they have lost accuracy after this process is done to their barrel. I really like all the positives, but I am afraid to mess up a 450 dollar barrel.

 

[Matt Pitchon]

I have three nitrided barrels. Two were nitrided before they were shot, one a Krieger and the other a Shilen. Both shoot very well, although I don't have a before and after on these. The Krieger is on my spacegun, which got me to High Master. The Shilen is on a Palma rifle. If I miss points it has nothing to do with the barrel or nitriding.

The other barrel is a Broughton which had about 100rds before the nitriding. It shot the same before as after the process.

My shooting is XTC, Palma, and Long Range. Barrel life is very important. But, my accuracy standards are not Bench Rest. For me 0.5MOA or better is just fine, and all my nitrided barrels can do this.

My highest round count nitrided barrel is the Kreiger at 3,500 rounds (223) and no change in the throat from new. Time will tell if this really works.

 

[Rtheurer]

This segment was from a NRA CMP Service rifle Builder. He has ten rifles out the door so far with the treatment done.


The first thing I did was investigate accuracy. NO change either for the better or the worse. Just no change.

Velocity appears to increase by a very modest 1%. I would be quick to caveat that these barrels are often tested weeks or sometimes months between naked vs. coated. The outside temps. can be much different as can the light conditions between tests. However, Joel K. also is finding the 1% increase independent from me. So, I am inclined to think the 1% number is somewhat valid but probably not of a hell of a lot of importance except in 1,000 yd. guns. Trying to shoot 80 gr. bullets out of 20" S.R. barrels at 1,000 yds. would be an example. Same, same trying to shoot Federal G.M. 175's at 1,000 yds. out of 20 or 22" barrels. Basically, guns just on the verge of going subsonic anyway. An extra 25 or 30 fps. with such guns could help some.



I got interested in the Isonite as much to guard against pitting as anything else because I was replacing damn near as many barrels from neglect as from wear out. I have not seen pitting in any barrels that I have been able to re-examine so I hope the nitriding will help with that problem some. I ran a Stoney Point on a barrel recently that had been in service for a year. Only .010" of erosion. Hell, I have seen barrels erode that much in a friggin weekend! No shit!


Lots of Hard data on file and a resonable cross section of rifles and more comming.
Hope this helps.
Russ T

 

[spclark]

Russ that's good stuff to know... thanks!

Melonite / Isonite are functionally equivalent I understand, the difference being a result of the source for the chemicals used.

You mention service rifle(s) so I have to assume AR's - is he having barrels treated without the barrel extension in place but with the gas port drilled, then mounting the extensions after treatment?

Somehow I doubt drilling a gas port on a treated barrel would be advisable, if it's even possible?

I was gonna have a new spacegun barrel treated early this year but backed out for fear of potential damage to the extension or the threads / sealant used. Otherwise I would have had to remove the extension after break-in but before treatment, then replace it post treatment with a great deal of care to get it timed right to the gas port.

As for break-in pre-treatment, yes - that's recommended by MMI-Trutec for one supplier. 40 - 50 rounds is usually sufficient.

 

[Rtheurer]

Yes these rifles are AR15's. And yes completly assembled, broke in and tested for function and group size on the machine rest. All data recorded on EVERY rifle and then completly stripped to include the barrel extension, then sent in and treated. Then reassembled and retested for function and group size on the machine rest and ALL data recorded, and retained for future studies.

I have a 6.5X284 barrel that has been coated that just hasnt made it to the rifle yet. A deployment and now the trip to OZ has put it on the back burner. I believe that rifle would be the true test of how the treatment works, as its a 1000 yard Rifle in a chambering that is hard on barrels.

Russ T

 

[kennyg]

This is great information guys, thanks a lot and keep it coming!

 

[RW]

does anyone have a list of places that do the nitrading process and what is the cost? I know that when the shot show report came about you had to have a large minimum order!
Is there any one who has the contact info and prices of some of the places that they have delt with?
Thank You RW

 

[Matt Pitchon]

MMI Tru-Tech does this work. The contact is:


Rodney Lanier: rlanier77@hotmail.com

- or company phone: 870•236•6920

- for most recent information. Prices he quoted me are $60 for a rifle barrel, $75 for a handgun, $55 for shot gun barrel + $20 for return shipping.

Keep in mind all machine work (chambering, crown, etc.) must have been done prior to processing....

 

[lloydx2]

What happens when erosion eats its way through the Nitriding? If You have .010 Push it already has. So now you have two different hardness of alloys. And will one continue to erode faster than the other? Time will tell.

 

[spclark]

What happens when erosion eats its way through the Nitriding?

Good question. Given the relative newness of experience with this (at least dating from when MMI-Trutec did their Shot Show announcement last year?) users who'd be in a good position to know would have to have shot a significant number of rounds thru their treated barrels unless they retire them well before any sign of imminent failure.

I know John Whidden's a fan... let's see if I can get some end-user info.

 

[CPorter]

DLC/Casidium is supposed to be the same as industrial hard carbon coating and the companies I have contacted use PVD that is not suitable for doing barrel bores.