# nitride finish barrels



## GREENCOUNTYPETE (Jul 25, 2006)

I was doing some lite reading and cam across some talk of Nitride fishish of barrels , there seems to be different processes but the salt bath nitride is the one discussed 

the barrel is heated in a bath and the metal is surfaced hardened and given coresion resistance 

I happen to have a nitride finish barrel although I didn't buy it because of that , 
there is talk that people are putting a documented 10K + rounds of 223 through a nitrided barrel without loss in accuracy , seeing much more minimal throat errosion than in an untreated barrel of the same steel.

the article seems to confirm that the process has no negative impact on accuracy , and definitely increases corrosion resistance 

https://www.shootingillustrated.com...the-pros-and-cons-of-nitride-barrel-finishes/


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## Chuck R. (Apr 24, 2008)

I've got one also from Larue Tactical.

Works as advertised. I've also got 1 Nitride AR BCG and it is easier to clean than a standard.

Chuck


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## Bearfootfarm (Jul 13, 2006)

GREENCOUNTYPETE said:


> there is talk that people are putting a documented 10K + rounds of 223 through a nitrided barrel without loss in accuracy


I could see that being true if it wasn't very accurate to begin with.


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## GREENCOUNTYPETE (Jul 25, 2006)

not sure what their standard was.

one that I was reading about claimed to still be able to hold the 200 yard slow fire x ring which looks like it would put it at 1.5 moa or less 

it did sound like he used a relatively light load as his goal was shooing tight groups at 200 and no further he had a different load for the 600 yard that he shot much less of 

so in this guys case it probably had more to do with keeping his velocity at 2800fps with a 55gr bullet he could easily be under 40K psi and as a result have much longer barrel life


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## Chuck R. (Apr 24, 2008)

I think the general comparison is Nitride VS Chrome lined, not Nitride VS SS or standard steel. It's when compared to Chrome lined, it shines especially from an accuracy standpoint. Faxon Arms has a good Q&A section on Nitride:

http://faxonfirearms.com/blog/frequenty-asked-questions-nitride-vs-chrome-lined/



> Which is more accurate?
> 
> Both can be precise, but Nitride will always be more accurate all things being equal. Nitride “locks in” the bore, chrome will add material to it. Chrome providers have gotten very good at this over the years, the adhesion of chrome is not perfect and there will be a small degradation in accuracy, though it may not be noticed. This is mitigated somewhat by those electropolishing, but one cannot perfectly plate chrome.
> 
> ...


Chuck


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## GREENCOUNTYPETE (Jul 25, 2006)

Chuck are you saying Nitride is approximately equal in life to chrome lined but without adding material 

and that chrome lined while typically not quite as accurate out of the gate will last 33% to 50% longer than the life of an untreated SS or chromoly steel barrel 

I realize these are generalizations and cleaning practices and neglect are more likely to reduce life for most people than they will ever get to in round count.


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## Chuck R. (Apr 24, 2008)

GPC, 

From what I've read, that's pretty much the gist of is.

Chuck


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## GunMonkeyIntl (May 13, 2013)

Chuck R. said:


> I think the general comparison is Nitride VS Chrome lined, not Nitride VS SS or standard steel. It's when compared to Chrome lined, it shines especially from an accuracy standpoint. Faxon Arms has a good Q&A section on Nitride:
> 
> http://faxonfirearms.com/blog/frequenty-asked-questions-nitride-vs-chrome-lined/
> 
> ...


I’ve got extensive experience with nitrided barrels through a couple different government weapons programs, both as a replacement for SS in precision weapons, and chrome-lined 4150 in carbines. It has its own advantages, and challenges/limitations over each. 

In the ‘Win’ column, nitrided 4150 is significantly more corrosion resistant than 410/416 or the Parkerized external surface of a chrome lined 4150 barrel. 

Barrel life CAN be greater, but it comes with a caveat. In high-pressure, throat-eroding cartridges, with relatively low RoF, it can extend barrel life significantly. A .338 LM/.338 NM/.300WM type caliber might go from 1,000-1,100 rounds to 1,200-1,500 rounds. 

In carbines, it’s a little different story. 

Many/most government agencies are requiring, and testing to 20k rounds on carbines- including the short-barreled ones that don’t have so much runway between the throat and the muzzle. Granted, there is usually an allowable loss of accuracy, but your 20k barrel still better not shoot like poo. 

A recent solicitation, which is pretty exemplaray of the requirements coming out now, was for a 10-12” 5.56 barrel, starting out at no greater than 2 MOA, and printing no worse than 4 MOA at 20k rounds. The accuracy testing was all conducted with a 77gr match load, and the high-rate firing done with a mixture of M855 and M855A1. The firing schedule is 50:50 SA and FA, with the FA portion being 120 rd evolutions of 3-5 round bursts, with 1 second between bursts. Considering the RoF and load, this is pretty aggressive. 

A well-made chrome-lined barrel will survive it just fine. If it starts at <2 MOA, you can expect it to be at 2.5-3.5 MOA at the end. The nitrided barrels I’ve seen subjected to testing like this haven’t fared as well. 

Which brings up the biggest shortcoming of FNC. It’s hard, it’s corrosion resistant, and it’s dimension-controlled, but, when it wears, it WEARS.

I’ve seen nitrided short-Carbine/PDW barrels (well made and properly done), subjected to a firing schedule like the one described above, completely shot out by 8k. And, I don’t mean shot out as in “not as accurate as it used to be”, I mean 180 deg. keyholes and a 0.2235 plug gauge dropped in the chamber falling out the muzzle. 

Chrome-lined 4150 is still the king of Battle-Rifle Hill. 

On lower RoF platforms it’s not as big a deal, but still presents its own problem. Where a 4140/50 or 410/416 barrel will let you know that it’s going over the course of 500 or 1000 rounds (maybe 200-300 in a magnum caliber), a nitrided one that starts out fine on one magazine may be keyholing-dead by the end of the next magazine (and I’m using 10 rd precision rifle mags in this example!). When a nitrided barrel goes, it’s already gone by the time you realize it. That can ruin a hunt/mission. 


The problem, I think, is in the surface of the treated product. I’m no engineer, but I have scoped hundreds of nitrided barrels, new, used, and done, to compare to a lifetime of looking into chrome-lined and bare ordnance-steel barrels. A brand new, properly made, and lovingly prepared nitirided barrel will look, to anyone with experience scoping barrels, like it’s heat-checked before its ever fired a round. Because...well, it kinda is. 

A barrel going into the nitride tank has got to be properly polished and honed before it goes in, and it’s still going to come out rough. The manufacturer actually has to repolish after nitriding or the induced surface finish will pick up so much copper that you’ll get pressure issues inside of 50 rounds of normal shooting. 

Even after the secondary polish, a nitrided barrel will never look as nice inside as a barrel well-made by any other means. It doesn’t necessarily hurt accuracy, but there’s no way it’s helping it. 

And I think the surface finish is what causes the abrupt barrel-death. Once a couple little bits of that super-hard alligator skin break off and get dragged down your already aging barrel embedded in a high-velocity copper lap, the converted-surface just starts flaking right out of it. A few rounds later, you’re done. 

For things like slides and bolt-carriers, it’s great- no reservations. What it does for your barrel does not come without a cost, though. Don’t get me wrong, I’ve got several nitrided barrels, and appreciate them within their limitations, but they do have limitations.


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