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Lug1
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Posted: 1/30/2013 10:11:08 PM
[Last Edit: 1/30/2013 10:43:11 PM by Lug1]
I commented on a chrome lined barrel thread and introduced the melonite concept to the OP. It got another comment. I did not mean to hijack his thread.

So I thought I would start this thread-- I have a brand new AR Performance 16" midlength socom. Haven't shot it yet. Should be in a position to start shooting it soon.

My question is does anybody have any comments(i actually meant real life experience, i've actually read every imaginable article on melonite and then some) as to wear and advanced round counts on Melonite vs chrome lined? For that matter does anybody have any comments on accuracy with Melonite vs chrome lined? Please comment on you Melonite vs chrome experience. Hopefully this heads off any hijack of the OP's thread.

by the way my AR Performance barrel really appears to be very well made. I cant wait to shoot it. My current set up has an 18" stainless that is very good about punching 1 hole (maybe slightly larger than a normal 5.56 hole). I worry about shooting my stainless out though with round count.
Saddlerocker
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Posted: 1/30/2013 10:34:47 PM
Well on paper Melonite should be the best of both worlds.
Claimed to be Durable as chrome or close to it and no loss of accuracy.

However, most people never shoot out a barrel so its hard to judge durability, and the quality of the barrel that is melonited will determine the accuracy. There may be top shelf chrome lined barrels that will be more accurate than a melonited one of lesser quality.
bobweaver
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Posted: 1/30/2013 10:38:22 PM
[Last Edit: 1/30/2013 10:44:25 PM by bobweaver]
From ARP:
Why did we choose to nitro-carburize our barrels instead of chrome lining them?
Nitro-Carburizing, Melonite, QPQ is a heat treat process for barrels that harden the barrels to apx 70 Rockwell so they last longer, are more corrosion resistant inside and out and it also decreases friction in the barrel which can increase velocity. Chrome lined barrels can decrease accuracy as it is a built up layer inside the barrel. Nitro-carburizing changes the structure of the metal without building a layer in the bore increasing performance but,not decreasing accuracy. The S-Carb treatment we use on use SS barrels is a slight modification to the QPQ process.

Melonite treated barrels have proven to last 30% longer than chromelined barrels and are more accurate
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ricochet7
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Posted: 1/30/2013 11:23:58 PM
Melonite (nitride) does offer benefit over chrome, I do not see that chrome offers anything over nitride. There have been many threads here and on other boards on Nitride vs CL, that and choice of weapon lubes seem to get people butt-hurt sometimes.
I either own or have owned 4 rifles with Melonite treated barrels, it definitely offers merit. Doesn't mean I'll get rid of my CL barrels, but I will tend to use melonited barrels more as I phase them in. Superior barrels uses their Hard Blue nitride QPQ and I will say that is some tough stuff. DSA offered melonited barrels and my Spikes 5.45 upper is melonited as well.
Barrel life (as stated before me) is longer than CL, have heard 30%+ from several people. But, as stated also before, most will not shoot out their barrels. When they nitride treat a barrel, it is inside and outside, so this is one less step than chroming and parkerizing a barrel. I believe we will see more and more meloniting in our future.
There is a lot of info all over the web if you look, and many services offering it.
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Blain
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Posted: 1/31/2013 12:28:41 PM
I have heard that salt bath nitriding, while under a light to moderate firing schedule, should have a similar "life" to a chrome lined barrel. However, under extreme firing schedules, the throat will erode more quickly than a chrome lined barrel.
TaylorWSO
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Posted: 1/31/2013 12:55:33 PM

Originally Posted By Blain:
I have heard that salt bath nitriding, while under a light to moderate firing schedule, should have a similar "life" to a chrome lined barrel. However, under extreme firing schedules, the throat will erode more quickly than a chrome lined barrel.


I'm gonna find out, I have a 10" 5.45 barrel on a m16 I just got last week. Its had 1080 through it in 3 range trips. I will burn it up by the end of the year.
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Lug1
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Posted: 1/31/2013 6:59:31 PM
I would be interested in seeing the tests on the throat eroding faster than chrome. I am not a metalurgist nor have I done scientific studies, but I have seen a lot of reports that show they are getting 60-70 rockwell on the barrel steel and its actually the steel and not a coating. I am not saying your wrong but I have not seen that study. I was just looking for somebody who had real life experience with it to report on it.
oryx
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Posted: 1/31/2013 8:18:01 PM
[Last Edit: 2/2/2013 10:13:09 AM by oryx]
We use both hard chrome plating and salt bath nitriding on products at work and the nitrided parts definitely last longer and are less prone to damage. In the industry I work in the nitrided parts have a rockwell hardness that exceeds that of the chrome plating. Running a nitrided or tool steel part over a Crome part would shave the chrome plating off. It is also better at impact.

Chrome is a plating on the surface that is very hard. Salt bath nitriding actuay changes the molecular structure and surface hardness of the actual metal and generally penetrates the surface deeper than chrome plating would cover the surface. For instance chrome plating may be .003" thick while nitriding may penetrate and change the properties of the steel .011".

I dont have the experience with nitrided barrels yet, but I believe the application may work well. I too am interested in Results and would put my money on the nitriding if done correctly. Nothing wrong with chrome lining, however.

I have also visited a nitriding plant and have visited their tribology lab years ago. The test results and comparisons are quite impressive. I asked them about a firearms application and they said they worked with some major manufacturers and governments, but would not reveal names or applications because of confidentiality.
uxo2
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Posted: 1/31/2013 8:55:29 PM
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ShannonD
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Posted: 1/31/2013 8:56:03 PM
Salt bath nitriding is no new concept, correct me if I am wrong, but the military tested this long ago. Under extreme heat and duration I do believe chrome won out in the tests conducted. The military fired those barrels to failure in the tests conducted. Don't get me wrong I love my melonite barrel it acts much like a normal barrel does accuracy wise and as many of you have pointed out its surface is identical to that of normal steel, but harder than whores heart. Mine drives nails nearly at 100 yards and usually acts pretty good even when hot. It just boiled down to me on what I want to use it for. I have chrome too that I love. I think honestly that the melonite will do just as well with better accuracy over chrome for what I shoot. Ill never be able to duplicate even in my wildest dreams what the military tests was in deciding what type of barrel to outfit with. They litterly fired them to failure 30,000 plus rounds until failure. There is no way in hell I will be able to get my barrels that hot.
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Posted: 1/31/2013 9:06:02 PM
[Last Edit: 1/31/2013 9:12:05 PM by WVHunter1s1k]
Don't forget to clean the barrel before first use.

Here is a video of the process:
[youtube]http://www.youtube.com/watch?v=8QjbOZAx2mw[/youtube]

Sorry, I couldn't make it work.
Lug1
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Posted: 1/31/2013 9:36:18 PM
Since we are all speculating or hearing, I read the study the military or D.O.D did in years ago(60's?). If I recall they didn't use the QPQ (quench polish quench) techniques of today. I may not be accurate in the specific there, but I recall a detailed rebuttal by a metalurgist who insisted the technology used back in the day is much improved in todays market. I am sorry for the lack of specifics. I have read so many articles on this, they all run together.
Here is what I know high performance auto part manufacturers are going to it. On paper it is incredible. And no offense to anybody posted I appreciate all the input and taking nothing for granted, I was just really interested in any individuals with first hand real world experience.
I read enough on paper to actually convince me to buy what I consider a very good barrel did the research on it too. I will post my experience when a get a few thousand rounds down range.
Having said that I am not a full auto shooter.

Thanks to all and looking forward to hearing more.
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Posted: 1/31/2013 10:15:08 PM
There were a number of torture tests run by Superior Barrels...

http://www.superiorbarrels.com/Barrel%20Testing/Barrel%20Testing.htm
Lug1
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Posted: 1/31/2013 10:25:53 PM
[Last Edit: 1/31/2013 10:27:30 PM by Lug1]
I had read that one before. Quite the "superior" results. I wasn't sure what to make of it as they had a purpose of selling their barrels. Not by any means saying it is false though. One of the reads that convinced me to buy a melonited barrel. Just went with a different brand. A bit less expensive. Had seen a couple of positive ARP reviews.
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Posted: 1/31/2013 10:54:50 PM
[Last Edit: 1/31/2013 10:55:45 PM by AAMP84]
Originally Posted By Lug1:
I had read that one before. Quite the "superior" results. I wasn't sure what to make of it as they had a purpose of selling their barrels. Not by any means saying it is false though. One of the reads that convinced me to buy a melonited barrel. Just went with a different brand. A bit less expensive. Had seen a couple of positive ARP reviews.


I pretty much went thru the same thing you did, picked up that same barrel last month. I was planning to already have it built, but the panic put that on hold. I also picked up a Centurion Arms mid barrel with the "twice-thick" chrome-lining. Honestly I don't see myself putting enough rounds thru these barrels to wear them out, especially since I'm gonna have a handful of rifles to shoot. Both barrels are high quality, and I doubt I'll regret purchasing either. The ARP barrel is gonna be for a recce build and the CA barrel is gonna be an all purpose/hard use build where it will be more than accurate enough.

ShannonD
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Posted: 1/31/2013 11:44:46 PM
[Last Edit: 1/31/2013 11:48:43 PM by ShannonD]
Real world results are they are accurate, plain and simple. It really does act like a normal steel barrel. My throat after a tad over 3000 rounds is still like new. I don't do a lot of mag dumps though. My M&P 15T usually gets pampered to death as that is the rifle I try to group with. It has been that accurate. It is a 5R barrel, how much that contributes to the accuracy, I don't know. A lot of long range shooters use 5R rifling now so it can't be bad.
One last thing OP if you reload you can shoot a nice medium speed, low flame powder like WIN748 and help barrel life a lot, especially on that stainless.
pavlovwolf
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Posted: 2/1/2013 1:27:12 AM
OP, the melonite barrels with the poly 5R rifling will also show an increase in speed over SS or Chrome lined barrels. This is essentially exactly what many of us that were building racing engines in the 80s and 90s were doing to the cranks and other high stress , high friction components. It was sold as Nitride treatment then.

The ARP 6.8 , 16" barrels routinely give speeds with factory ammo that are in the same range as stainless and chrome 20" barrels. I'm not sure how much of that is the chamber, but a good bit is the combination of the rifling and the melonite.

This is something I have seen with my own eyes, on a chrono.

I have a 16" ARP recon upper, with that process and it is superb. You will also find that Harrison is tops when it comes to CS as well.

The index pin in the barrel/extension on mine came loose, and I sent it back. It arrived there today at lunch. In the midst of all of this madness, Harrison stopped what he was doing, completely stripped my rifle down, cleaned it up, and reassembled it, test fired it, and boxed it up, and shipped it back out this afternoon.

Time in from USPS was 1pm today. I got the email on 68forums from him telling me the issue and what was done at around 3pm. You cannot beat that. Plus, he boxed up a shirt with it. I will have my upper back by Friday and I mailed it out Monday.

One thing to mention.

You won't need to use a brush to clean it. In fact, don't use a brush. If you have to use one, use a nylon brush.
Otherwise , use a good copper remover. He has recommendations on his site, but I can't usually find that around here. The thing is, it is easier to get clean that any of the chromed barrels I have ever owned. Generally a few patches in and it's done.

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Lug1
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Posted: 2/1/2013 10:03:54 AM
[Last Edit: 2/1/2013 10:05:00 AM by Lug1]
I believe Harrison is the guy I have emailed with. Wow top notch working guy! You are right to say his CS is good. Didn't know me from Adam and treated me, I thought, like a long time returning customer. Was very patient with me while I was tire kicking asking questions.

To the other guy above posting about the Centurion barrel, we did the same exact thing. I picked up my ARP first and originally thought I was scoring the Centurion for a buddy, he didn't need it though. So to date I have paired the Centurion barrel with a cmmg lower, an aero precision upper and have a magpul MOE stock so far. Slowly building my work horse like you!
ricochet7
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Posted: 2/1/2013 11:35:32 AM
[Last Edit: 2/1/2013 11:36:26 AM by ricochet7]
My hardest used AR nowadays is the 5.45 Spikes melonited rifle, I have about 8500 rounds through it so far, being everything from mag dumps to slower aimed fire. There is no signs of it showing wear in any way so far, it's just a workhorse/training rifle that was used due to previously 7N6 (cheaper, corrosive ammo). So far that melonite barrel holds up to wear and corrosion well (and my abuse).
The 2 melonited DSA uppers were 16", one a middy and one a carbine, both were good shooters, depending on ammo of course with the edge going to the carbine. I put about 2000 rounds apiece on those before letting friends talk me out of them.
And, then there is my Superior barrel 18" Hard Blue that is a tack driver, just changed glass and installed a SD-E trigger. It'll shoot better than my capabilities. A file will just dance on it's surface, I do hope it will hold it's edge like they say- I treat it better than my others.
So, my 4 barrels and 13,000+ rounds haven't really proven a lot in real life except to me. Harrison will probably be sending me an ARP 6.8 before long, I've come close but something always comes up (like no bolts or money spent). He is a super guy.

My belief is meloniting will do nothing to make a bad barrel better, but will make a good barrel better when done right. There may indeed be uses where CL is better suited, but for accuracy and long range, meloniting has it's place. Mag dumps do not melt it, but maybe squad weapons would burn thru it faster- I'll never know. Yeah, OP I'm like you, have tried to read everything I could on the process. Found info where the Brits process apparently was used for early tests, which has been improved on since the early 60's.
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Posted: 2/1/2013 11:54:56 AM
Chrome plating stuff is getting really expensive and the shops capable of doing high quality barrel plating are always backed up.
Melonite coating is relatively inexpensive and and there's more and more shops doing the work.

I'm not going to speculate about barrel life... Except to say that Stellite is still king shit.
I know that the military has experimented with with everything including tungsten carbide and ceramic/metallic and none have proven satisfactory.
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Posted: 2/1/2013 9:14:04 PM
Let me add one more thing.

My upper was on my doorstep today. Getting ready to put it back on the lower and set it back up.

I shipped this thing out on the afternoon of the 28th. It got to AR Perfomance around 1pm on the 30th. Harrison stopped what he was doing, completely went through the thing, repaired it, tested it for cracks, flaws , reassembled it and fired it, and emailed me at 3pm telling me what the issue was, and that he had it boxed back up and was shipping it out. I got it today.

That is incredible service. Even without a panic, that is incredible service, but when people are behind filling 6 months to a year of orders and building things, that is absolutely fantastic.

I have felt so naked these last few days without this thing being loaded up sitting on the couch behind me.

Just ate supper, got to go and get my lower and optics and all and put it back together. See ya.
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northpark
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Posted: 2/2/2013 2:29:22 AM
[Last Edit: 2/2/2013 2:31:08 AM by northpark]
I'm not educated on the subject but I was under the impression that my glock barrel was nitrated along with my adam's arms upper (w/ bcg)

Both have wear past the nitriting down to bear metal in less than 1k rounds, but my chrome bolt carrier and barrel extensions in all of my ar's have zero visible wear after easily 5k

Just take this as an uneducated experience by me - most of this wear is nitrated metal vs nitrated metal, however there is some curious wear on the hg's feed ramps
Gamma762
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Posted: 2/2/2013 2:57:14 AM
Originally Posted By northpark:
I'm not educated on the subject but I was under the impression that my glock barrel was nitrated along with my adam's arms upper (w/ bcg)

Both have wear past the nitriting down to bear metal in less than 1k rounds, but my chrome bolt carrier and barrel extensions in all of my ar's have zero visible wear after easily 5k

Just take this as an uneducated experience by me - most of this wear is nitrated metal vs nitrated metal, however there is some curious wear on the hg's feed ramps

It's not "wear" really, just the surface coloration changing/polishing. What looks like bare metal is still the nitrided steel, the case depth on salt bath nitride usually runs something like .015 IIRC. Feed ramps is bullet jacket material rubbing off on the steel.
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northpark
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Posted: 2/2/2013 4:01:17 AM
Originally Posted By Gamma762:
Originally Posted By northpark:
I'm not educated on the subject but I was under the impression that my glock barrel was nitrated along with my adam's arms upper (w/ bcg)

Both have wear past the nitriting down to bear metal in less than 1k rounds, but my chrome bolt carrier and barrel extensions in all of my ar's have zero visible wear after easily 5k

Just take this as an uneducated experience by me - most of this wear is nitrated metal vs nitrated metal, however there is some curious wear on the hg's feed ramps

It's not "wear" really, just the surface coloration changing/polishing. What looks like bare metal is still the nitrided steel, the case depth on salt bath nitride usually runs something like .015 IIRC. Feed ramps is bullet jacket material rubbing off on the steel.


good enough then, this isn't any area of my studies

i've heard that this whole nickle boron stuff was translucent
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Posted: 2/2/2013 7:44:11 AM
Originally Posted By bobweaver:
From ARP:
Why did we choose to nitro-carburize our barrels instead of chrome lining them?
Nitro-Carburizing, Melonite, QPQ is a heat treat process for barrels that harden the barrels to apx 70 Rockwell so they last longer, are more corrosion resistant inside and out and it also decreases friction in the barrel which can increase velocity. Chrome lined barrels can decrease accuracy as it is a built up layer inside the barrel. Nitro-carburizing changes the structure of the metal without building a layer in the bore increasing performance but,not decreasing accuracy. The S-Carb treatment we use on use SS barrels is a slight modification to the QPQ process.

Melonite treated barrels have proven to last 30% longer than chromelined barrels and are more accurate

I have one nit to pick with ARP's blurb. Perhaps in the 1970s it was possible that chrome lining a barrel might reduce its accuracy potential due to irregularities or unevenness, but the industry has a very long track record to work with, and with several decades worth of experience plating AR barrels, I do not see how any barrel maker would accept irregularities or uneven plating today,

With that said, it seems that nitro-carburizing is "the best of both worlds" in terms of simplicity in production and robustness in use. (I don't like salesmen who "out a little extra icing on the cake" by adding inaccurate or misleading information to their pitch, especially when the facts already make the sale,)
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Lug1
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Posted: 2/2/2013 9:48:23 AM
[Last Edit: 2/2/2013 10:35:03 AM by Lug1]
I don't mean to nit pick your statement but ARP says " built up layer" and "which can". One statement is a fact true it is a built up or added layer if you will. The other say which can which is an indefinite. Maybe some barrels are less accurate and some aren't because of it. I would say that covers all the bases. It may be riding the fence but it is not untrue.
Your supporting evidence is "I do not see how".
Now that I have nit picked you, and I am very sorry if it was offensive to you it's not my intention, I just wanted to say his statement appears to be factual although somewhat riding the fence with the "it can" statement. Again no disrespect I just don't like to see somebody pointed to as wrong without supporting factual evidence. I would be very open to reading any articles or studies you have on this matter.
Harrison is a great guy to deal with. The barrel I have is in "my opinion" great craftsmanship. I cannot wait to shoot the snot out of it.
Have a great day.
Also, thank you for your service!!
Originally Posted By GHPorter:
Originally Posted By bobweaver:
From ARP:
Why did we choose to nitro-carburize our barrels instead of chrome lining them?
Nitro-Carburizing, Melonite, QPQ is a heat treat process for barrels that harden the barrels to apx 70 Rockwell so they last longer, are more corrosion resistant inside and out and it also decreases friction in the barrel which can increase velocity. Chrome lined barrels can decrease accuracy as it is a built up layer inside the barrel. Nitro-carburizing changes the structure of the metal without building a layer in the bore increasing performance but,not decreasing accuracy. The S-Carb treatment we use on use SS barrels is a slight modification to the QPQ process.

Melonite treated barrels have proven to last 30% longer than chromelined barrels and are more accurate

I have one nit to pick with ARP's blurb. Perhaps in the 1970s it was possible that chrome lining a barrel might reduce its accuracy potential due to irregularities or unevenness, but the industry has a very long track record to work with, and with several decades worth of experience plating AR barrels, I do not see how any barrel maker would accept irregularities or uneven plating today,

With that said, it seems that nitro-carburizing is "the best of both worlds" in terms of simplicity in production and robustness in use. (I don't like salesmen who "out a little extra icing on the cake" by adding inaccurate or misleading information to their pitch, especially when the facts already make the sale,)




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