Chrome-lined Barrels: What is the most accurate?

[LilGucci]

There are a lot of sales going on, and I'm interested in a barrel for one of my AR-10 builds. A stainless steel barrel would be better for accuracy but I'm planning to run & gun this particular light-weight AR-10 like an AR-15 and am attracted to the barrel life of a chrome-lined barrel.

Who makes the very best 308 chrome-lined barrels? My priorities are accuracy, first, and weight second. And if all Chrome-lined barrels are not the same, please explain why your suggestion is a cut above the rest.

The only one I was thinking about was LMT's 20" chrome-lined barrel. I've heard that Stag, Criterion, and a few other companies make them too, but do any of you have experience with them and can speak on behalf of their accuracy?

 

[srt-4_uk]

You realize the one pictured only works in a MWS and not a "normal" AR10, right?
As easy and inexpensive it is to swap a barrel, I wouldn't care about chrome lined. But that's just me.

 

[DRAM40A1]

You realize the one pictured only works in a MWS and not a "normal" AR10, right?
As easy and inexpensive it is to swap a barrel, I wouldn't care about chrome lined. But that's just me.

Right....if you shoot enough 308 to shoot out a barrel, the cost of that barrel is insignificant.

 

[smoothy8500]

Barrels are an expendable item like tires on a muscle car...Use them hard and replace.

 

[Cheyenne Bodie]

~1 MOA can be had easily if your build is on point. Much less than that is not the norm, but who cares— probably 70% of the folks here can't pick up a battle rifle and even hit 10 inches at 1000 anyways. There certainly are some who can, but it doesn't really have shit to do with a chrome lined barrel. I'm a proponent of the more precision is always better approach, but practical LR accuracy has more to do with optics and experience than remarkable barrel accuracy.

 

[Strykervet]

KAC is the ONLY mfg. I know of that will chrome line a cut rifle barrel. Best of both worlds.

I think they still come with the sub 1MOA guarantee too. Not cheap, not by a long fucking shot and you'll need the whole upper, not just the barrel. KAC LOOKS like an AR, but it jumped the tracks a long time ago and is mostly a proprietary system now. You can't go wrong with one of those uppers though, or a whole rifle for that matter, they just ain't cheap.

Not sure if you could custom order one. Call Krieger and see what they say?

But I'm in the barrel change camp. I like precision shit and if I wear it out or have to use it as a blaster, fucking whatever man. I'll change it when I get around to it. In fact, almost all my rifles have SS barrels, SBR's, whatever. Noveske is one of my go-to's BTW. Lilja is hard to beat and Krieger is the titties.

A chrome lined hammer forged barrel will be the toughest, last the longest and probably perform better than other chrome lined barrels mfg.'d other ways but I'm not sure who makes one for an AR10.

 

[JMGlasgow]

I've heard Criterion has accurate AR barrels.

 

[RUTGERS95]

I've been very impressed with the LMT 16 and 18" cl barrels I've shot. Both shot sub moa with quality ammo and right at moa with Dag

 

[RyanScott]

SR-25 is the answer you seek.

 

[XLR308]

Just go with a reputable maker that nitride treats thier barrels.
Better wear and corrosion resistance than Chrome without the issues that chrome lining can have.

 

[RyanScott]

Less heat resistance.

 

[RUTGERS95]

Just go with a reputable maker that nitride treats thier barrels.
Better wear and corrosion resistance than Chrome without the issues that chrome lining can have.

so much wrong with this reply. Aside from the issues of 'before nitriding' but would like to see your data on the comparison of wear and corrosion resistence because Hendersons is on record on tos stating chrome has held up longer than nitride barrels. No testing on the planet will exceed his place.

 

[XLR308]

so much wrong with this reply. Aside from the issues of 'before nitriding' but would like to see your data on the comparison of wear and corrosion resistence because Hendersons is on record on tos stating chrome has held up longer than nitride barrels. No testing on the planet will exceed his place.

Just a few of the articles I have read can be found with a quick search and many more I'm sure with some digging around.
In comparison of wear and corrosion restistence there is no way in hell that an untreated exterior barrel steel is tougher or more corrosion resistant than a nitride barrel when coated with phosphate.
Then there is the issue of accuracy potential of both barrels, while a chrome lined barrel can be as accurate as a nitride treated barrel that often is not the case due to dimensional differences created from a plating process on a barrel bored and rifled over sized as opposed to a finished product with only a surface treatment.
Some companies have mastered the chrome lining process for sure but there are several problems with chrome lining that can manifest if not applied perfectly that just don't exist in the nitriding process.
It is also a more expensive and labor intensive process than nitriding with a lot of toxic chemicals left over from the process that should be considered and really feel it is just old technology that at some point will be and should be replaced.
For full auto machine guns I'm sure that chrome lining will hold its place in that area but that's not what the OP was asking about.

Still hearing just crickets over here.

Frequenty Asked Questions: Nitride vs. Chrome Lined

Curious about the comparison of chrome lined vs nitride? We dig into the question more in this blog and discuss the right barrel for you.

faxonfirearms.com

An Official Journal Of The NRA | The Pros and Cons of Nitride Barrel Finishes

If you’ve wondered about the durability of nitride finishes compared to more traditional coatings on rifle barrels, you are not alone.

www.shootingillustrated.com

 

[roamin]

so much wrong with this reply. Aside from the issues of 'before nitriding' but would like to see your data on the comparison of wear and corrosion resistence because Hendersons is on record on tos stating chrome has held up longer than nitride barrels. No testing on the planet will exceed his place.

Hey can you drop a link for that testing I'd love to read it. Thanks.

 

[roamin]

I've heard Criterion has accurate AR barrels.

Criterion (top video) doesn't look that impressive to me a few machining marks and several imperfections at the bases to the lands. Compare that the flawlessness of a Krieger (bottom video) and it's no contest.

 

[RUTGERS95]

The Krieger is cut rifled.

Lots of CR barrels look that way in a bore scope, and yes a Krieger is pretty top notch.

I did learn that unless you have a problem, the borescope isn't all that big of a deal. I have seen some mighty rough looking excellently shooting barrels.

I was inspecting a rifle that the owner said "shot 1" only on a good day" from a company known for .25 guns. Upon inspection I found ridiculous cleaning rod marks going all the way through the throat and into the first 4" of barrel. And that was all she wrote.

True...everything looks ugly under a borescope to me

 

[LilGucci]

I no longer care for chrome-lined vs stainless steel, as barrel swaps seem to make that concern irrelevant.

But what about the cold-hammer-forged barrels vs stainless steel debate? Many of our allies in NATO seem to have made the switch over to it, and according to SmallArmsSolutions, is a superior option to stainless, but in what applications?

 

[RyanScott]

CHF is best for high rates of fire or cold weather.

 

[Ravenworks]

I have several Criterion barrels and all perform.
I met them at Camp Perry one year and learned a lot from Josh.
When Krieger owned them they did all the military barrels.
They actually scoured the country and bought up all the old equipment they needed and rebuilt it.
Something nice about owning a 100 year old gun and having a replacement barrel made on one of the original pieces of equipment.
The second thing that is great about the company is that the phone is a answered by the 3rd ring by a human that knows what they are talking about.
To me that alone is worth the extra
money on and expendable product.
Ps, they are making the replacement barrels for CMP.

 

[RyanScott]

And longevity in barrel burners oddly. The CHF Sako 338LM barrels had a hell of a life compared to the traditional ones if I remember right.

True. The Finns rebarrel their Sakos every four thousand rounds just in case.

 

[MontanaMan]

CHF is best for high rates of fire or cold weather.

And for high volume production rates as it's fast & relatively cheap per unit to produce barrels; downslide is the high capital cost for the equipment which makes it mainly suited to large barrel producers like FN, Remington, Sako/Tikka, etc.

CHF makes a very smooth finish barrel with good dimensional accuracy.

MM

 

[LeadZeke]

Chroming is no better than nitriding unless you have a belt-fed. Just get a nitrided barrel (which will also be more accurate) or pay to have Craddock nitride one for you.

CHF matters a hell of a lot less than the material used and the precision and rate of change of the mandrel. You can make shitty CHF barrels just like you can make shitty button barrels. Sadly, no one in the US takes the time to make really accurate CHF AR15 barrels. Hodge's FN specs might be the closest, but no one is shooting quarter-sized 10 round groups with those either.

 

[RUTGERS95]

Chroming is no better than nitriding unless you have a belt-fed. Just get a nitrided barrel (which will also be more accurate) or pay to have Craddock nitride one for you.

CHF matters a hell of a lot less than the material used and the precision and rate of change of the mandrel. You can make shitty CHF barrels just like you can make shitty button barrels. Sadly, no one in the US takes the time to make really accurate CHF AR15 barrels. Hodge's FN specs might be the closest, but no one is shooting quarter-sized 10 round groups with those either.

not sure about more accurate as I've seen some cl barrels that are like ss accurate and some nitride barrels that were $hit.

I think Henderson on arfcom said the cl were holding up longer than the nitride...I think

 

[Merle]

KAC LOOKS like an AR, but it jumped the tracks a long time ago and is mostly a proprietary system now.

Not really though. I'm using both KAC and LMT parts on my Mega Maten rifle.

 

[MK20]

Criterion Nitride match barrel.

 

[LeadZeke]

not sure about more accurate as I've seen some cl barrels that are like ss accurate and some nitride barrels that were $hit.

I think Henderson on arfcom said the cl were holding up longer than the nitride...I think

Yeah, and I've seen $90 PSA barrels put out <1moa 10 round groups. SOMETIMES you get really lucky and the stars align and you get a good barrel form a bad process. But this is a game of probability; will X barrel likely be more accurate than Y? On average, even with the best processes chrome lined barrels will not be as accurate and will not stay as accurate as long (under semi-auto use) as nitrided barrels (again using the proper treatments on good barrels).

There are shit nitrided barrels too, hence my "buy from a quality manufacturer" statement.

 

[RyanScott]

There are also different chrome lining processes. The older one electrically erodes steel and replaces it with chrome. A newer process uses an oversized bore and adds chrome to it in a more uniform fashion.

 

[MontanaMan]

The older one electrically erodes steel and replaces it with chrome.

No it doesn't & that's not quite accurate or correct with regards to chromium plating itself.................

Chromium plating itself is an additive coating, always has been, always will be.

In some chromium plating processes, for some parts, a reverse current etch may be used for adhesion purposes & to chemically activate the surface before the actual plating cycle begins, & depending on parameters used, it's conceivable that some material could be removed before the plating is applied, so it's possible that you are just confused or mis-informed or no expressing your thoughts coherently.

Given the dimensional tolerances desired on barrels, the people doing the plating would establish the reverse etch parameters to absolutely minimize any measurable material removal as it cannot be uniformly controlled. It would not be possible to consistently & accurately attempt to "erode steel" & then replace a like amount with chromium layer.

And yes, besides being intimately involved with plating & thermal spray coating processes, at an engineering & technical level, I have also actually been in a facility where Colt barrels were being plated.

MM

 

[RUTGERS95]

Yeah, and I've seen $90 PSA barrels put out <1moa 10 round groups. SOMETIMES you get really lucky and the stars align and you get a good barrel form a bad process. But this is a game of probability; will X barrel likely be more accurate than Y? On average, even with the best processes chrome lined barrels will not be as accurate and will not stay as accurate as long (under semi-auto use) as nitrided barrels (again using the proper treatments on good barrels).

There are shit nitrided barrels too, hence my "buy from a quality manufacturer" statement.

absolutely not true, nitride doesn't guarantee squat as the qc behind any barrel is more important than it being cl, ss, unlined, or nitride. It's a blanket statement that is simply unfounded unless you can prove otherwise with unbiased and controlled testing.

I certainly appreciated probabilities being a math buy myself but the variables behind the defined probabilities are what determine mean sets.

just look at the process for what criterion uses before nitriding. Most class shooters won't nitride till they know they've got a ss barrel that is a shooter

about the only thing anyone can say for sure is nitrided barrels will last longer than ss for shoot counts assuming of course we're not talking about elements as we all know most are babying their tools

 

[RyanScott]

No it doesn't & that's not quite accurate or correct with regards to chromium plating itself.................

Chromium plating itself is an additive coating, always has been, always will be.

In some chromium plating processes, for some parts, a reverse current etch may be used for adhesion purposes & to chemically activate the surface before the actual plating cycle begins, & depending on parameters used, it's conceivable that some material could be removed before the plating is applied, so it's possible that you are just confused or mis-informed or no expressing your thoughts coherently.

Given the dimensional tolerances desired on barrels, the people doing the plating would establish the reverse etch parameters to absolutely minimize any measurable material removal as it cannot be uniformly controlled. It would not be possible to consistently & accurately attempt to "erode steel" & then replace a like amount with chromium layer.

And yes, besides being intimately involved with plating & thermal spray coating processes, at an engineering & technical level, I have also actually been in a facility where Colt barrels were being plated.

MM

You should offer your services to Criterion, apparently they are doing it wrong.

Chrome Lining vs. Salt Bath Nitriding: Which Barrel Finish Is Better? - Criterion Barrels

One of the most frequently asked questions by shooters pertains to the difference between our barrels with chrome lining and salt bath nitriding.

criterionbarrels.com

 

[346ci]

I forgot about chrome lined barrels when I sold the last Colt M4 barrel I had stashed away(2008-ish). While they did shoot good and the barfcom guys loved them, I changed paths to seek a more accurate barrel. Most are from ARP-melonited and some stainless from Hawk Hill. I don't see another chrome lined barrel in my future..

 

[MontanaMan]

You should offer your services to Criterion, apparently they are doing it wrong.

Chrome Lining vs. Salt Bath Nitriding: Which Barrel Finish Is Better? - Criterion Barrels

One of the most frequently asked questions by shooters pertains to the difference between our barrels with chrome lining and salt bath nitriding.

criterionbarrels.com

Pure marketing BS as well as an author's explanation of a process that they obviously do not really & fully understand.

What "was" done is completely & inadequately explained in order to make what Criterion (correctly) is doing now sound like a major or significant improvement.

If they were really wanted to do it right, they'd lap both before & after plating.............it really doesn't clarify whether they do that or not.

They are only applying a very thin chrome layer but even though it's tenths of a thousandth, it simply not possible, on thousands of barrels, to get each & every bore plated end to end to the same tolerances that can be done via machining.

Anyone who believes that doesn't understand the process, & with no post-chrome processing to regain dimensional control, a chrome lined barrel made by anyone, by any process can never equal the tolerance capability that be achieved via machining.

Salt bath nitriding, theoretically, does not change dimensions but I've seen change in some type of parts, both with salt & gas.

From the article:

"When researching salt bath nitrided barrels it is not uncommon to come across a wide variety of reports on the varying level of performance you may see from barrels utilizing this treatment method. This is largely a result of how many manufacturers go about finishing their bore and chamber, as well as how the salt bath nitride process is executed."

The above statement illustrates the problem, & it's a 1000 times worse with plating & various plating shop & plating processes (baths & chemistry).

While that article may be directionally accurate, it leaves out a ton & a wealth of details. And yes, for your edification, I had a hand in developing the advanced type of plating baths used by most major volume production operation for technically advanced plating operations.

So believe whatever BS you choose to believe; for me, if I want an accurate barrel, I'll buy bare stainless, if I want durability, I'll buy chrome lined or nitrided.

MM

 

[RyanScott]

I haven’t argued that chrome is as accurate...although you can make a half minute chrome lines barrel if you want to.

 

[MontanaMan]

I haven’t argued that chrome is as accurate...although you can make a half minute chrome lines barrel if you want to.

I don't know about 1/2 MOA, but surely by lapping to a dimension, plating, & lapping again to a dimension, it can be better, but lapping will only lap the lands, not the groove too.

I have little doubt that Criterion is making as as good of a CL barrel as has ever been made, (& FN is good too).

My heartburn comes in the statement that implies that lot of material was etched away before plating & that's a pretty gross exaggeration & misrepresentation of the process..............not that it isn't possible, but it's not likely.

No reflection on you; you were only reading & reporting & it's a pretty detailed issue for anyone no familiar with it................didn't mean to insult you directly, my apologies if I did.

MM

 

[RyanScott]

How is the FN SPR chromed? They are 1/2” guns as are HK 416s depending on barrel profile.

 

[MontanaMan]

How is the FN SPR chromed? They are 1/2” guns as are HK 416s depending on barrel profile.

Yeah, I have an FN barrel that is very good.

I've not seen anything specific on FN's plating process, so I can't say with absolute certainty.

What I can say is that it's likely the same as Criterion & I do believe that FN laps after plating, as it seems that I read that somehwere at some time.

Plating facilities, today, are very expensive & have lots of environmental regulations & permitting issues to deal with, so overall, the number of shops doing it has fallen significantly. And the number of really high-tech places doing it is relatively small & the tooling, fixturing & technique to do barrels is demanding & expensive.

So I don't know if either Criterion or FN have captive plating shops or if it goes to a sub-contractor; it's very possible that the plating for both could be being done in the same place.

MM

 

[LeadZeke]

absolutely not true, nitride doesn't guarantee squat as the qc behind any barrel is more important than it being cl, ss, unlined, or nitride. It's a blanket statement that is simply unfounded unless you can prove otherwise with unbiased and controlled testing.

I certainly appreciated probabilities being a math buy myself but the variables behind the defined probabilities are what determine mean sets.

just look at the process for what criterion uses before nitriding. Most class shooters won't nitride till they know they've got a ss barrel that is a shooter

about the only thing anyone can say for sure is nitrided barrels will last longer than ss for shoot counts assuming of course we're not talking about elements as we all know most are babying their tools

I'm....not sure you are reading my posts thoroughly. I'm saying that nitriding DOESN'T make a barrel more accurate. You still have to get a good blank. What I am saying is that unlike chrome, it doesn't make the barrel's accuracy WORSE. Both extend life similarly. Hence, nitride is the superior treatment unless you have a belt-fed where chrome really starts to shine. Outisde of that, nitride is basically always a better choice all else being equal. Not sure how that didn't come through in the first two posts but I hope it is now clear.

 

[RUTGERS95]

all about the process and qc

I've FN barrels cl that are accurate, LMT 16" cl in 308 is under moa hitting .7 with 175gr and I've got some cl that are not. The same holds true for my nitride barrels but my unlined barrels are the most consistent shooters

I'm....not sure you are reading my posts thoroughly. I'm saying that nitriding DOESN'T make a barrel more accurate. You still have to get a good blank. What I am saying is that unlike chrome, it doesn't make the barrel's accuracy WORSE. Both extend life similarly. Hence, nitride is the superior treatment unless you have a belt-fed where chrome really starts to shine. Outisde of that, nitride is basically always a better choice all else being equal. Not sure how that didn't come through in the first two posts but I hope it is now clear.

it's possible I'm retarded, it has happened in the past. sorry for any confusion

 

[loveha]

I have no dog in this fight other than to say isn't the purpose of a CL barrel for durability more than accuracy? I didn't buy my Criterion CL barrel for accuracy. I bought it to put as many rounds down range at minute of man. If I was looking for accuracy, then I would have picked one of a dozen other great barrel makers that offered stainless.

 

[RUTGERS95]

I have no dog in this fight other than to say isn't the purpose of a CL barrel for durability more than accuracy? I didn't buy my Criterion CL barrel for accuracy. I bought it to put as many rounds down range at minute of man. If I was looking for accuracy, then I would have picked one of a dozen other great barrel makers that offered stainless.

wise man
of note however, cl process has changed over time and gotten better, more uniform and offers excellent accuracy now. With all things, it's in the QC

 

[LeadZeke]

Yeah, CL barrels can be accurate for sure. But they will always be X% less accurate than the blank, even with the best process. How much does that matter? Not much when you are only losing .2moa or .5moa. But you still lose. With nitride you don't (unless you fuck it up) so you can nitride a Bartlein and it will turn out every bit as accurate as it went in, just with more barrel life.

In other words: if there is a nitride option, why not get it (all else being equal)?

 

[hunter8793]

I have no dog in this fight other than to say isn't the purpose of a CL barrel for durability more than accuracy? I didn't buy my Criterion CL barrel for accuracy. I bought it to put as many rounds down range at minute of man. If I was looking for accuracy, then I would have picked one of a dozen other great barrel makers that offered stainless.

Oh god I guess I’m screwed. I bought a $300 Criterion Nitrided 6.5 Creedmoor barrel ?

 

[Ravenworks]

Oh god I guess I’m screwed. I bought a $300 Criterion Nitrided 6.5 Creedmoor barrel ?

You really are screwed because I just had a conversation in another thread with a guy that said Criterion sucks.
It's the internet and he thinks Krieger still owns them.

 

[theLBC]

i think if barrel life is more important than being .5 moa instead of .61 moa, fn chf cl barrels are a known commodity.
i'm told this could be a good option compared to other coatings if you expect rapid rates of extended fire.

for me, it just gives me comfort that my rifle will probably outlive me and defend the freedoms of the next generation.
i didn't buy it for play, but it turned out hard to resist.

 

[theLBC]

Yeah, I have an FN barrel that is very good.

I've not seen anything specific on FN's plating process, so I can't say with absolute certainty.

What I can say is that it's likely the same as Criterion & I do believe that FN laps after plating, as it seems that I read that somehwere at some time.

Plating facilities, today, are very expensive & have lots of environmental regulations & permitting issues to deal with, so overall, the number of shops doing it has fallen significantly. And the number of really high-tech places doing it is relatively small & the tooling, fixturing & technique to do barrels is demanding & expensive.

So I don't know if either Criterion or FN have captive plating shops or if it goes to a sub-contractor; it's very possible that the plating for both could be being done in the same place.

MM

possibly lining in forged into the barrel and then forged again for the rifling? not really plated except the chamber.

US6594936B1 - Method for lining a gun barrel - Google Patents

A method for lining a gun barrel with a material selected to reduce the rate of erosion and corrosion from the rounds of ammunition fired through it includes the steps of forming a rod of the lining material, hammer -forging a barrel blank to the rod, and then drilling out a bore in the rod. The...

patents.google.com

 

[The DFC]

My KAC 16" Cr plated blaster is a 1 moa shooter with good factory ammo-last session was Australian Outback SMK 69gr.

To date my LMT 16" Cr plated 308 has not been an moa shooter-but I'm working on it and I suspect a bench session with a scope with greater than 5x mag will give me a more true sense of what it can do.

 

[MontanaMan]

possibly lining in forged into the barrel and then forged again for the rifling? not really plated except the chamber.

US6594936B1 - Method for lining a gun barrel - Google Patents

A method for lining a gun barrel with a material selected to reduce the rate of erosion and corrosion from the rounds of ammunition fired through it includes the steps of forming a rod of the lining material, hammer -forging a barrel blank to the rod, and then drilling out a bore in the rod. The...

patents.google.com

Yeah, I've heard of that method, never read the patent before................could be, never seen one that I know of, but I'd expect that process to be significantly more expensive than plating for high volume parts.

MM

 

[The DFC]

possibly lining in forged into the barrel and then forged again for the rifling? not really plated except the chamber.

US6594936B1 - Method for lining a gun barrel - Google Patents

A method for lining a gun barrel with a material selected to reduce the rate of erosion and corrosion from the rounds of ammunition fired through it includes the steps of forming a rod of the lining material, hammer -forging a barrel blank to the rod, and then drilling out a bore in the rod. The...

patents.google.com

I'm not intimate with Cr lining of gun barrels but I am in the coating business. From what I know from a physics prospective it's all plating in some form-liquid transfer of Cr ions via an electrolytic solution to barrel or using a plasma-ionized gas method (PVD)(CVD) in a vacuum system to deposit on the barrel. You can also evaporate. At the end of the day it's all ions and biasing no matter the medium. The form factor of the barrel I'm sure is very challenging-I would think a liquid method would be the best. Again I'm not at all familiar with gun barrel lining.

 

[GhostFace]

About 13 years ago I had an Armalite AR-10A4 that had a medium CL barrel, I free floated it and feed it factory match ammo. It was a consistently .7-1 MOA shooter with ammo that it liked., like a fool I traded away that rifle. I burned out a barrel on my other AR-10T recently, I replaced it with a newer made Armalite CL barrel. My hope is that it will shoot as good as the old CL barrel that I had. Its wonderful how accurate a CL barrel can be...

 

[Ravenworks]

You could buy a Ballistic advantage barrel for less than $120 for a 308 and $80 for a 5.56 when they are on sale at Primary arms.
While you are at it if you're serious, you should order two so you have a spare to put away.