Nitrided stainless? [Archive] - M4Carbine.net Forums

dlraymond30

10-18-17, 19:39

Stickman

10-18-17, 21:25

Can any if the people that have experience with stainless barrels that are nitride/melonite treated chime in? Im interested to see and hear if it extends the life of the SS barrel to near chrome moly levels durability? Could be a great option if it does for the barrel what it doea for 4150.
What do you guys think?

Regards,
Darrin

I just had this conversation yesterday while researching an upcoming article. The end answer is that while it is desirable for some things, SS barrels are not one of them.

dlraymond30

10-18-17, 22:04

Can you tell me why? I see that several high end manufacterers are offering the option. Faxon makes a really nice one.

5.56 Bonded SP

10-18-17, 22:27

I just had this conversation yesterday while researching an upcoming article. The end answer is that while it is desirable for some things, SS barrels are not one of them.

I have heard the same.

Stickman

10-18-17, 22:45

Can you tell me why? I see that several high end manufacterers are offering the option. Faxon makes a really nice one.

The conversation involved a larger picture.

ColtSeavers

10-18-17, 23:06

Here's the thread that finally got us as close to an apples to apples comparison between chrome lined and melonited barrels thanks to FaxonNathan and Plouf/Mrgunsngear.

In it is also info about nitrided stainless.

https://www.ar●●.com/forums/ar-●●/-ARCHIVED-THREAD-Nitride-vs-chrome-lining/118-693734/?page=1

To fill in the missing bits, answer 4+11

Todd.K

10-18-17, 23:08

Can you tell me why?

Stainless barrels are not more accurate than CM.

Stainless offers a reasonable increase in corrosion resistance for a barrel that isn't coated. Barrels that are coated are not as accurate. Coatings take sharp edges and round them slightly, and are never more consistent than the base barrel.

Stickman

10-18-17, 23:52

5.56 Bonded SP

10-19-17, 03:18

Stainless barrels are not more accurate than CM.

Stainless offers a reasonable increase in corrosion resistance for a barrel that isn't coated. Barrels that are coated are not as accurate. Coatings take sharp edges and round them slightly, and are never more consistent than the base barrel.

Nitride is a treatment, not a coating so I don't believe that is correct. This is why some claim nitride is more accurate than chrome, and theoretically I can agree with the principal. From my shooting experience my nitride barrels seem to group more consistently... But nitride will never replace chrome on my defensive carbines.

If I recall correctly, certain ss barrels have charecteristics about the steel that help with precision shooting, however nitride changes the composition of the barring surface of the barrel where the bullet contacts which negates the positive attributes ss had in the first place.

But it's been so long since I read about this subject I could very well be mistaken.
I just remember that basically if you are looking to Cloverleaf groups, and you really want to shoot Precision to just go for an unlined stainless steel barrel.
If you just want to shoot 1-2 moa at 100 yards you probably won't see the benefit of a ss barrel.

5.56 Bonded SP

10-19-17, 03:25

I have heard some guys talk about breaking in a stainless steel barrel with a few hundred rounds, and then having it nitride treated afterwards. Those guys said they had good results.

Personally I think the time and money would be better spent on handloading your own ammo. I have 4150 nitride barrels that shoot submoa with handloads, but still shoot 2-4 moa with m855.
A nice ss barrel is a complete waste of money if you don't handload or buy really expensive factory ammo in my opinion.
I like handloading because I can make match grade ammunition that expands for about the same price as wolf steel case ammo.

Todd.K

10-19-17, 11:08

I can get into the specifics of conversion coatings vs etch and chrome but the basic point I made is true to both.

Stickman

10-19-17, 14:57

I can get into the specifics of conversion coatings vs etch and chrome but the basic point I made is true to both.

For people who are unaware, Todd was John Noveskes right hand man. Todd had direct knowledge, input, and workings with products (both public and unknown) of Noveske Rifleworks from the start. He was with Johnny while they were working out of his first shop (converted garage).

To say that Todd has an understanding of the AR15, as well as humility, would be an incredible understatement.

hdrolling

10-19-17, 17:15

So should my Faxon 416R stainless with QPQ nitride finish inside and out and 5R-EE be more or less accurate than a chromed lined barrel that's not 5R?

5.56 Bonded SP

10-19-17, 17:40

I can get into the specifics of conversion coatings vs etch and chrome but the basic point I made is true to both.

So nitride does round the edges ? That is very interesting, I was always told/believed the opposite was true. I was always told that Nitride type treatments doesn't effect the internal contours of the barrel at all, where as chrome does/can. I would love to hear your knowledge on the subject. It would be nice to have an industry professional give us some details. I know myself and many others have mostly just read speculations on the subject, rather than concrete data points.

AAMP84

10-19-17, 18:27

So does anyone have any info on barrel life of a melonite/nitrided stainless barrel? Seems like this thread went a little sideways. I had read that it makes the barrel slightly more durable but decreases the corrosion resistance of stainless steel. I have no direct experience though, so take that with a grain of salt.

dlraymond30

10-19-17, 19:05

id be very interested in either a readers digest version or the full monty breakdown of said specifics!

AR-556

10-19-17, 21:34

I would rather have a Nitride barrel. Leave the chrome lined barrels on the battle field.

dlraymond30

10-19-17, 21:47

Ive seen damn good sccurscy out of the Faxon ss bbl with nitride in 5.56 chamber.... Just sayin

joeg26er

10-19-17, 21:52

@dlraymond
What faxon barrel length twist and upper ?
What rounds and grouping?

Todd.K

10-19-17, 22:50

Sure, but it is never more accurate than before the coating. I'm not saying it's a bad barrel, but what is the stainless bringing? Because there is no reason a CM barrel can't be made to the same quality as a SS barrel. So why not take the better heat resistance of CM?

Yes and maybe on nitride reducing the corrosion resistance of stainless. I am not an expert, but I have talked with a few. It does in the conversion process remove the outer layer of chromium. But barrels are made out of some of the least corrosion resistant stainless grades anyway.

Torquetard

10-19-17, 23:13

I have a PWS mod 2 that is a laser with 62 gr stuff, shot some match ammo through it with great results to see if I didnt burn it out from shooting it too without letting it cool enough a bunch of times. "Utilizing only the highest quality 416R stainless steel barrel blanks, MK1 barrels are turned in house then lithium embedded salt nitro-carburized treated (FNC LIFE HD) for hardness and corrosion resistance." Theyre supposed to last around 18k without significant accuracy degradation. Im sure there are chrome lined whatever steel barrels out there that do .00001 MOA, not trying to turn it into that, or muh rifle is gud etc, but maybe they're onto something. I know they like to do stuff a little differently though

Stickman

10-20-17, 00:18

Ive seen damn good sccurscy out of the Faxon ss bbl with nitride in 5.56 chamber.... Just sayin

I have no doubt of that.

mdram

10-20-17, 08:37

just an opinion and a question, but if your doing chf or button, there may not be a big diff
but if cut rifling, the ss should be easier to machine
now what affect nitriding has? not sure
but even if it extended the barrel life, should it help with throat erosion?

hdrolling

10-20-17, 09:43

I'm going to go out on a limb here and say there is no issue with the coated SS barrels, their catching on. Mine shoots great.

If I was a company selling and making money on expensive chrome lined barrels then of course their not going to say "buy the other guy's cheaper barrels".

But watch how quickly they change their opinions after they see all the money their losing by not selling the SS barrels, and when they're not making as much a profit on the Chrome lined barrels eventually they'll start making the SS barrels.

Right now it's hold out and convince buyers not to buy SS as long as the money is still coming in.

dlraymond30

10-20-17, 10:02

Also since the rule of thumb for SS is "no mag dumps" why do companies like Noveske and Rainier make 7.5-14.5" SS barrels to be used in SBR's which are notoriously run hard? I understand that it is because there is always a demand for options besides the accepted norm but I wouldn't think that a super high end company like Noveske and Rainier would make 5.56 barrels as short as 7.5".

Regards,
Darrin

Todd.K

10-20-17, 10:49

So nitride does round the edges ?

Yes. All coatings have some effect on sharp edges, both conversion and plating types. Some remove and some build up edges.

AAMP84

10-20-17, 11:05

Yes. All coatings have some effect on sharp edges, both conversion and plating types. Some remove and some build up edges.

Everything I've read from the companies that do nitriding and people that use it regularly say that it does not change the dimensions of the barrel. It is a surface treatment and not a coating. What you're saying about it removing some of the built up edges makes sense, but I've never heard anything about that. If what you say is accurate, do you believe that it has a significant effect on the barrel's accuracy?

MegademiC

10-20-17, 11:58

Everything I've read from the companies that do nitriding and people that use it regularly say that it does not change the dimensions of the barrel. It is a surface treatment and not a coating. What you're saying about it removing some of the built up edges makes sense, but I've never heard anything about that. If what you say is accurate, do you believe that it has a significant effect on the barrel's accuracy?

It’s a treatment that forms a conversion coating. It forms a layer of iron(ferric/ferrous?)-nitrides down to a certain depth.

I will defer the accuracy comment to others.

MistWolf

10-20-17, 12:58

5.56 Bonded SP

10-20-17, 13:06

Pretty sure my dad's 300 win mag is SS...

I have no doubt ss can take some abuse.

Cold/Bore

10-20-17, 18:46

I have no reason to doubt anyone’s experience with their nitrided SS barrels being accurate/durable but most of the personal experience being used as evidence of accuracy/durability of these treated barrels are sample sizes of one. This is not enough to convince me of the benefits of a nitrided SS barrel. Not that I oppose the idea of a more durable and accurate barrel. I would be more inclined to listening to industry professionals like Todd.K who work with far larger sample sizes.

MegademiC

10-20-17, 21:12

What is the appeal of nitrided stainless? If high volume, is it more durable than CL?
If not, is it more accurate, corrosion resistant or durable than nitrided cmv?

5.56 Bonded SP

10-20-17, 22:16

Little off topic but...

I have a nitride 4150 CrMoV barrel that has shot multiple ~ .7'' five shot groups with hand loads at 100 yards. I don't think I am physically capable of shooting better without a mechanical rest, and I don't think my handloading equipment would be able to produce ammo that shot better either.
I'll see if I can find one of the targets later tonight. Barrel is from Areo, 18'' rifle length.

OP do you handload?

dlraymond30

10-20-17, 22:37

No I do not handload yet. I have a nitrided BA 16" Hanson Profile .625" that has shot .6" groups with factory PPU 75gr and .77" with Federal Gold Medal 77 gr SMKs.
I also have an 18" SS BA Rifle Length "Ops 12" barrel that I HAVE NOT shot yet because I have not had enough $ to purchase a decent variable powered optic but what got me to buy it was having a chance to group another shooters build and could not believe what it was shooting with Black Hills mk262! Measured with a ruler it was ~1/3" best 3 shot group (yes I was doing "internet commando" grouping) and I had zero experience group shooting with an AR so, needless to say, I was impressed! Can't wait to get an optic to finally start running mine!
BTW, I actually did the proper "break in" procedure on my 16" nitrided Hanson barrel mentioned above and I was getting those amazing groups... Hell, with factory Winchester 45gr (yes, 45gr out of a 1/7) at 54 yards with and unmagnified Holosun 403A from prone using my range bag as a front rest and a bag of rice as the rear, I got a 1/3 inch group!!!!!! Can you believe that? I was literally giddy!!!!

-Darrin

snaggletooth

10-20-17, 22:39

I remember reading that the way the barrel is Nitrided can make a difference. As the different types to "Nitride" a barrel can bring to different temperatures. Such as a salt bath, which is what QPQ (quench polish quench) can bring a barrel into a temperature range where it can adversely affect the characteristics of that type of metal for the barrel. Generally speaking, you do not want to bring stainless above a certain temp (it differs depending on the composition of the metal. Often why most people say that nitriding generally benefits high carbon steels, is because it is more resilient to the heat/ able to have more hardness stability in that high heat that QPQ nitriding introduces to the metal.

There is also gas nitriding, and also plasma nitriding. For stainless I remember reading that plasma nitriding was the best way to apply onto the metal, as it is a lower temp allowing for the metal to not change its properties.

I also remember reading that the purpose of nitride originally was to enhance the mechanical application of a metal, ie make it a harder surface. So the properties of stainless barrels being easier to machine and then nitriding would allow for that barrel to maintain its accuracy for a longer period that if it were untreated. The fact about increasing corrosion resistance sometimes applies sometimes it is adversely affected. I don't know if anyone remembers the stainless smith and wesson M&P slides that were rusting, those were nitrided (however, the wrong application for applying the nitride properties (someone correct if I am wrong) was used). I believe if the M&P slides had used something that didn't change the properties it would have had better results with the corrosion resistance issue.

I have had several stainless barrels that I have sent out to be nitrided. I assembled them in uppers, shot them to break in and have the barrel settle down. Once I believe I got the barrel to be at a point where the little burs and imperfections have worked itself out and the accuracy just hits the right spot for me. I take the upper apart and send them to be plasma nitrided. Just look up plasma nitriding or ion nitriding and you will find a bunch of places that can do that for you. It isn't cheap, but I thought "what the hell?" It wouldn't hurt to try

vicious_cb

10-22-17, 00:59

What is the appeal of nitrided stainless? If high volume, is it more durable than CL?
If not, is it more accurate, corrosion resistant or durable than nitrided cmv?

It shouldnt be since a barrel's overall toughness is based on the substrate material rather than the coating. What kills a barrel is throat erosion. The coating or surface treatment wont last long in the throat so the base steel will start to matter sooner rather than later. CMV handles heat much better than stainless so there is no reason to use stainless in a high volume application whether its treated or coated or not. Correct me if Im wrong Todd K.

As far as corrosion goes 416R has pretty shitty corrosion resistance anyway, I found that out the hard way after leaving a stainless steel barreled AR in my trunk overnight the condensation on the barrel was enough to cause rust spots to form.

Todd.K

10-22-17, 18:59

CMV handles heat much better than stainless so there is no reason to use stainless in a high volume application whether its treated or coated or not.

As far as corrosion goes 416R has pretty shitty corrosion resistance anyway, I found that out the hard way after leaving a stainless steel barreled AR in my trunk overnight the condensation on the barrel was enough to cause rust spots to form.

Correct. Stainless softens at a lower temperature and softer metal erodes faster.

416 is stainless enough for most uses. It's not pretty when you get some surface rust but it takes a long time for it to be anything but cosmetic. And the bore is a polished finish and so more corrosion resistant than a rough outer finish. All my stainless barrels are KG or polished outside.

I don't have any large number comparison data, sorry.

So I'm clear, I don't have a problem with nitrided SS barrels. Given them not being run too hot, they should have a somewhat longer accurate lifespan, at somewhat less accuracy than uncoated SS barrels. To quantify those "somewhat's" is where it gets harder.

Besides the cost of ordering 4150 CMV in quantity, the better product for this in between SS and CL, based on what I know, would be a 4150 match barrel with nitride.

dlraymond30

10-22-17, 20:24

I have 5 m&p pistols and none of them have ever had any issues rusting and i have had them in extreme conditions because i love them but i do believe you are correct with some of the earlier ones.

everyone, thanks so much for all the help and info on this topic!