S&W Melonite coated barrel vs Noveske chrome lined barrel.

[Dirtyboy333]

Yeah when I say that i think I see the "move is already starting" I just mean that I see alot more people offering it than I used to. It's seems like every week there's another company offering it along side other barrels.

Also, I don't know of any of the top teir "milspec" companies like DD or BCM offering it and it's probably because, well, it's not "milspec". Middies aren't milspec either but the customers pretty much demanded that. I don't really see any1 demanding QPQ.

Add S&W's "tactical" model (M&P 15T)to the list according to their 2011 catalog I just picked up. I know there's more that I'm forgetting about.

I wouldn't be surprised if we see a top teir maker offering it as an option soon. What about BCM's Ionbond, are they plasma NTC'd?

[Fabius]

CMMG's "WASP" treatment is also some form of nitrocarburizing.


From the list above it seems that this treatment is used by inexpensive models on the one hand (S&W, CMMG, DSA) and boutique more expensive models on the other hand (all others), and as far as I know is not currently used on a mid to high end upper in an ordinary DI AR-15 configuration, with the sole exception of the uppers from Superior Barrels, on which I have no reputational information.

Fabius, I couldn't find any information about an "SA58 CTC" on DSA's website or on google. I know that DSA had been offering nitride treated L1A1 barrels for a brief period of time, but apparently not right now. Do you have any more information on this model? Most of the SA58 models have a 4150 steel barrel that is cryo treated but not, to my knowledge, given any surface treatment like chrome or nitriding.

I found that reference on a Gunsite website, but just checked and realized that its for Gunsite South Africa. Its an announcement that the U.S. State Department has approved their import of 2 DS Arms rifles, the SA58 and the ZM4 Midlength. This is the link: http://www.gunsite.co.za/forums/show...68-DS-ARMS-USA

The post is dated 3/26/11 and states the following:

"SA58 CTC Rifles = the very well known DSA FAL rifle.

The SA58 is enhanced over the FN FAL. It features a fluted 16" barrel, Nitride coated bore, greatly enhanced trigger, enhanced SAW pistol grip, alluminium lower receiver, enhanced iron sights, flat top dust cover/optic mount, quad rail forward grip and short gas system."

The post also has the following information:

"Patric Sweeney in his Book The AR-15 Volume 3 says:

-"the nitride coated barrel/bore shrugs off corrosion. In testing they have had shooters who have kept match grade accuracy well beyond the life of a hard-chromed barrel. Some shooters have reported barrels that lasted into 25'000=30'000 round range".

Also, the new S&W M&P 15T, MSRP of $1,159, is now using the same barrel as the Sport - Melonite treated, 1:8 twist, 5R rifling. The 15T probably qualifies as a mid-tier AR.

[Fabius]

Yeah when I say that i think I see the "move is already starting" I just mean that I see alot more people offering it than I used to. It's seems like every week there's another company offering it along side other barrels.

I wouldn't be surprised if we see a top teir maker offering it as an option soon. What about BCM's Ionbond, are they plasma NTC'd?

I noticed that the first nitride treated barrels were offered on expensive "specialty" rifles like the ACR. The barrels were promoted as superior to chrome lined barrels. None of the manufacturers claimed that it was more expensive to make, but that was the implication from their marketing claims.

S&W and DS Arms seem to have been the first to offer nitride treated barrels in mid and lower priced AR's. I saw a statement from S&W earlier this year that the Sport barrel was actually less expensive to make than a chrome lined barrel, but offered comparable or better barrel life and improved accuracy. They have since removed that statement from their website.

I suspect that nitride treatment is less expensive than chrome lining while potentially offering a superior combination of durability, accuracy and velocity. It seems to be a smart choice for the civilian market, but I doubt that you'll see any manufacturer admitting that it is "cheaper" than chrome lining because too many in the AR community will assume that cheaper means "inferior."

I also suspect that once we see some real world data on the durability of these barrels in the AR platform, the market will respond. I know that I would be reluctant at this point to pay extra for a chrome lined barrel if I could get a nitride treated barrel on the same platform.

[m4brian]

Not having handled the Smith with a nitrided barrel, do they do the whole thing - inside and out - this would be nice...

I would bet Smith steps out and starts offering it in all their ARs.

I'd also like to see some more reports of the accuracy with these barrels.

[ricochet]

CMMG's "WASP" treatment is also some form of nitrocarburizing.

Just to summarize and add a few, the list of currently marketed ARs or uppers with some form of nitrocarburizing treatment seems to be:
S&W M&P15 "Sport" model
CMMG - LE Series with WASP treatment
DS Arms (most ZM4 models and ZM4 uppers, but they also offer plain CM and chrome-lined on certain styles)
LWRC
POF-USA
AAC
Adams Arms (uppers)
Huldra Arms (rifles and uppers with chrome-moly barrels {not stainless})
Bushmaster ACR (no other models)
Sig - 550-556
Superior Barrels with "hard blue" (uppers and barrels) {http://www.superiorbarrels.com/}

From the list above it seems that this treatment is used by inexpensive models on the one hand (S&W, CMMG, DSA) and boutique more expensive models on the other hand (all others), and as far as I know is not currently used on a mid to high end upper in an ordinary DI AR-15 configuration, with the sole exception of the uppers from Superior Barrels, on which I have no reputational information.

Fabius, I couldn't find any information about an "SA58 CTC" on DSA's website or on google. I know that DSA had been offering nitride treated L1A1 barrels for a brief period of time, but apparently not right now. Do you have any more information on this model? Most of the SA58 models have a 4150 steel barrel that is cryo treated but not, to my knowledge, given any surface treatment like chrome or nitriding.

I have been reading this thread with extreme interest, I believe there is always room for improvement of anything man makes.
I purchased 2 of the DSA ZM4 nitrided uppers (1 carbine, 1 middy) when they first came out, found them to be decent. I consider DSA AR15 uppers to not be in anyones top AR catagory ( I do own several DSA FN-FAL rifles/receivers that are as good as any, not nitrided). I still prefer BCM, Noveske, and Spikes for my goto rifles because I trust what I know works. I also have a Spikes 5.45 nitrided upper that is proving to be pretty tough.
I purchased one of the Superior Hard Blue 18" Mk12 CLE contour barrels and just finished it's build, I must admit I like it's toughness and like what I read on these. I have only function tested this upper so far, waiting for a break in this heat to have a range day. I believe that everything comes at a cost- but I do not see that Nitriding detracts when compared to CL- so what do we give up by going Nitride compared to CL? CL offers benefits over non-CL for corrosion and wear, at a cost in accuracy. If Nitriding offers the same benefits without sacrificing accuracy, what is not to like?
I want to thank those who offer/offered information, I am learning a lot. There usually are valid arguments for/against any change, that's healthy.

[Fabius]

Not having handled the Smith with a nitrided barrel, do they do the whole thing - inside and out - this would be nice...

I would bet Smith steps out and starts offering it in all their ARs.

I'd also like to see some more reports of the accuracy with these barrels.

The barrel is melonite treated inside and out, including the chamber. I've only seen anecdotal reports of increased accuracy, mostly from new owners who have reported that the Sport seems more accurate than their other AR's. I'd like to see a side by side bench rest comparison of the Sport to an AR with a chrome lined barrel using the same ammo, etc.

[wolf_walker]

The barrel is melonite treated inside and out, including the chamber. I've only seen anecdotal reports of increased accuracy, mostly from new owners who have reported that the Sport seems more accurate than their other AR's. I'd like to see a side by side bench rest comparison of the Sport to an AR with a chrome lined barrel using the same ammo, etc.

I'd rather see two of them shot side by side on FA through a small fortune worth of ammo and then the bores inspected. It's almost a certainty that the accuracy isn't negatively effected, if it's positively effected it's a small amount. Longevity from hard use use is the thing...

[Leonidas24]

"Patric Sweeney in his Book The AR-15 Volume 3 says:

-"the nitride coated barrel/bore shrugs off corrosion. In testing they have had shooters who have kept match grade accuracy well beyond the life of a hard-chromed barrel. Some shooters have reported barrels that lasted into 25'000=30'000 round range".

That could very well be true but if my memory serves my correctly Filthy-14 lasted well into the 30,000's or beyond perhaps.

Take what Sweeney says with a grain of salt. He's part of the "just-as-good-as" crowd.

[SomeOtherGuy]

That could very well be true but if my memory serves my correctly Filthy-14 lasted well into the 30,000's or beyond perhaps.

Part of the problem with discussing barrel life is that there doesn't seem to be any universally accepted definition of "worn out." I read somewhere that the US Army considers barrels worn out (this may be only machinegun barrels) when the muzzle velocity is 20% less than with a new barrel. That's way beyond the point where I would consider a barrel worn out. Most civilian shooters are probably going either by accuracy, with a wide range of standards, or by throat erosion, which is easy to measure but not measured by most people. Some people may not consider a barrel worn out til bullets are keyholing, meaning they aren't engaging the rifling or the rifling is simply gone.

In other words, a barrel that's worn out by one person's standard may have half its life remaining by another standard.

If someone wanted to do a rigorous side-by-side test, I would measure all three standards - muzzle velocity, accuracy, and throat erosion - and report all three measures every 1k or 5k rounds so the reader could decide for themselves.

[rsilvers]

Sometimes barrel life is considered gone when the accuracy specs are no longer met.

Other times, when the rifle will close on a NOGO headspace gauge.

I never heard of the velocity one.