Barrel lining - beyond chrome lining

[TheFalconeer]

Gents,

I am looking to go beyond hard chrome for barrel lining; having seen some problems with chrome-lined barrels recently. On dozens of 5.56 barrels, chrome is teared from throat & muzzle after roughly 3000 rounds...pretty disappointing.

So, I am studying the various "new" treatments now existing. Of course, there is nitriding, so widely used today. But is there anyone who tried Co-P-SiC coating ? (US patent US2012/0247962 A1)

I am not a chemist but, from what I understand, it would be a pretty good candidate to replace hard chrome for barrel lining.

[opngrnd]

Are there accuracy or velocity problems with the barrels you are referring to ? I'm just curious, since most people like their chrome lined barrels.

[ABNAK]

I would also have to ask who made the chrome lined barrels the OP mentions?

[VIP3R 237]

LiFe is a new treatment that Parker Trutec is offering, they advertise it as the next generation of ferric nitrocarburizing. I have a cobalt kinetics barrel that is LiFe treated that hopefully I can get some high round counts through.

‘LiFe Process offers in comparison to our traditional nitride, creates a smoother (less porosity) surface finish, this imparts higher corrosion resistance and lubricity characteristics. The hardness and depth are almost identical to the QPQ process. Most firearms manufacturers are reporting a major increase on wear properties also. In my opinion the oxide is also a deeper black with the LiFe process. This process is unique to Parker TruTec MMI and the Tennessee plant we are the only company in the U.S. doing anything like this using nitrocarburizing.’

[opngrnd]

We all know that's going to happen for any chrome-lined Barrel. I'm just wondering if that's part of the normal life or if he is seeing problems earlier than normal. I don't know what the generally accepted service life from a chrome-lined Barrel that has not been abused is, but I would expect past 10,000 rounds. I could be totally wrong.

[hk_shootr]

Ive never seen a QUALITY chrome lined barrel peel at 3k.

Would like to hear of all these barrels the OP is talking about.

[prepare]

According to the description on this chrome lined barrel it has a 20,000 round service life. I happen to have this one and its stamped FN.

The CHF collection of barrels from Spike’s Tactical are known for their incredible durability. Cold hammer forging hardens the steel around a rifled mandrel, which creates the lands and grooves of the barrel. Each barrel blank is certified CMV material and hard chrome-lined to the M249 SAW mil-spec for a thickness close to 2x as much as a mil-spec M4. That thickness gives this 5.56-chambered, 11.5” barrel a 20,000+ round service life!

[lysander]

Stellite liners?

Tantalum lining? (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&cad=rja&uact=8&ved=2ahUKEwjVrfvju-LhAhVI7qwKHRr0D2QQFjAJegQIBhAC&url=http%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fdownload%3Fdoi%3D10.1.1.383.8949%26rep%3Drep1%26type%3Dpdf&usg=AOvVaw1tpZH7QYrDYAEoT5LWu5TV)

[AKDoug]

Ive never seen a QUALITY chrome lined barrel peel at 3k.

Would like to hear of all these barrels the OP is talking about.

I as well. I haven't ever seen a chrome line barrel peel at any point. It isn't like cheap ass bumper chrome. I've seen them worn through and eroded away, but that was always pretty much past the 10K mark.

[TheFalconeer]

Well, those are, indeed, FN barrels. M249 type.

The old ones, some made 30 years ago, are still going strong but dozens of the new ones are keyholing after only a 2-3 thousand shots.

And it's true keyholing, with 25 rounds keyholing out of 30 shots fired at a 15m-away target.

[vicious_cb]

Well, those are, indeed, FN barrels. M249 type.

The old ones, some made 30 years ago, are still going strong but dozens of the new ones are keyholing after only a 2-3 thousand shots.

And it's true keyholing, with 25 rounds keyholing out of 30 shots fired at a 15m-away target.

Unless I missed it somewhere are you saying your FN CHF barrel lasted less than 3k? Which vendor did you buy it from? Who does the chrome lining just as or more important than lining itself.

[vicious_cb]

Never mind I found it. OP bought a turd and is dealing with the consequences.

There is nothing wrong with chome-lining and you do not need something "better", stop buying shit barrels and you wont run into this issue.

https://www.m4carbine.net/showthread.php?210185-Need-help-ID-this-upper


This post is suspect. He posted elsewhere about some pseudo Colt turd that was purchased that wasn't really a Colt.

[TheFalconeer]

Nope, those are two totally different case.
The pseudo-Colt were assembled in Italy by a company called Prima Armi.

But the M249 barrels were provided by with Minimi MGs.

[vicious_cb]

Nope, those are two totally different case.
The pseudo-Colt were assembled in Italy by a company called Prima Armi.

But the M249 barrels were provided by with Minimi MGs.

So lets be clear, you have Minimi belt fed machine gun thats burning barrels in less than 3k rounds?

[TheFalconeer]

THAT. And not only one. At least a dozen.

Let's see what we have:

56965
56966
56967

[georgeib]

Could you post some pictures of the weapons and the barrels, including the markings on the barrels please?

[hk_shootr]

Gents,

I am looking to go beyond hard chrome for barrel lining; having seen some problems with chrome-lined barrels recently. On dozens of 5.56 barrels, chrome is teared from throat & muzzle after roughly 3000 rounds...pretty disappointing.

So, I am studying the various "new" treatments now existing. Of course, there is nitriding, so widely used today. But is there anyone who tried Co-P-SiC coating ? (US patent US2012/0247962 A1)

I am not a chemist but, from what I understand, it would be a pretty good candidate to replace hard chrome for barrel lining.


It seems you have let out a bit of vital info.

Few barrels will hold up to 249 fire and not have a greatly decreased life
Suspect your simply burned them out, you are trying to compare apples to kiwi

[Eurodriver]

This thread is stupid.

[Wake27]

I as well. I haven't ever seen a chrome line barrel peel at any point. It isn't like cheap ass bumper chrome. I've seen them worn through and eroded away, but that was always pretty much past the 10K mark.

My Noveske barrel was doing it at 3k rounds. They acknowledged that it was a defect and replaced it, but it did happen.


THAT. And not only one. At least a dozen.

Let's see what we have:

56965
56966
56967

Were all 3k of those rounds fired on cyclic without a single barrel change or period to allow the barrels to cool?


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[MegademiC]

If you are getting it hot, the substrate is eroding. No treatment or coating is going to make a big difference on that.

Chipping or peeling Cr is a production process issue and there is a lack of adhesion.

[jpmuscle]

So questionable barrels being used under questionable circumstances is being questioned?


Seems legit


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[Todd.K]

But the M249 barrels were provided by with Minimi MGs.

If you legitimately have Minimi machineguns you should be in contact with FN about your barrel problem.

[GH41]

Wearing out a barrel with three thousand rounds at 750RPM would take 4 minutes of sustained fire if he had a belt that long. Am I the only one who smells fish??