AR Barrel : Nitride or Hard Chrome ?

[McBuck]

I have a choice of either a hard chrome 18"bbl or a 16" Nitride.
The 18bbl is 1:7 M4 upper straight bbl.
The 16" is an M4 upper & profile nitride bbl.
I won't be shooting any comp with this gun. pure SHTF, plinking, hog hunting, coyote shootin, throw in the seat gun.
I am looking in the BB @ CMMG.

I know the platform pretty welll, but a lot of new stuff has been done to em since 86' to make em better, and I don't know what a "nitride bbl" is. I do like a M4 profile a little better, and I like a 16"bbl better too.

 

[taliv]

are you talking about the chamber/bore or the outside?

 

[McBuck]

"1/9 twist Barrels are Nitrided inside and out for years and years of trouble free operation! "

C&P from the page.

 

[Bartholomew Roberts]

A nitride finish is supposedly similar to the Tennifer finish on the Glock. It is the hip new thing in barrels and is supposed to dramatically increase barrel life; but I've yet to talk/see anybody who really shoots hard and has a nitrided barrel, so the only thing I know about them is Internet rumour.

 

[Z-Michigan]

Glock barrels are nitrided, if I understand correctly. And nitriding is being used by some decent brands like LWRC.

IMHO, nitriding is good and potentially has long term durability benefits over hard chrome. However, I don't think it will make any difference for your stated uses, or frankly most other uses. I wouldn't have it be a deciding factor.

 

[The_Hammer_Man]

TiN plating or "Nitriding" as it's popularly known is , IMHO, an improvement over standard chrome treatments of barrel.

For one.. you can use a thinner layer of it to achieve the same result.

For two.. It's much slicker than hard chrome. Doesn't flake off under stress and doesn't crack either.

 

[Zerodefect]

Either coating is fine.

The Bargin bin rifles have proved to be better than what you pay for usually when you consider what a gun store would mark the same same rifle up to. Sure they might have a scratch or two, but my Colt looked the same way after a single class.

Get the 1/7 18" if you plan on useing it for defense with 70+gn ammo. I'm stuck on 1/7 so i'd go with the 18" model.
Get the 1/9 16" for lighter ammo. I prefere 16" barrels but don't really like 1/9.

So maybe I'd just flip a coin. Whats more important to you? Weight/length, or barrel twist?

 

[Z-Michigan]

TiN plating or "Nitriding" as it's popularly known is , IMHO, an improvement over standard chrome treatments of barrel.

Totally different processes, fyi.

Titanium Nitride is a typically gold-colored coating seen on a lot drill bits (especially marketed to consumers) and is also offered on a few AR-15 bolt carriers, e.g. from DPMS. It is a surface coating.

The nitriding process being used more and more in the firearms industry is actually a form of case hardening, using both carbon and nitrogen impregnation to make the surface of a steel very hard. It is a surface conversion process, not a coating like TiN or hard chrome. As such it can't flake off from the part. It is typically not quite as hard (Rockwell C: 56-66, typical) as hard chrome (Rockwell C: 70), but is still very hard and quite useful.

http://en.wikipedia.org/wiki/Carbonitriding

Its major benefit to the user is that as a conversion process, the barrel (or other part) can be milled to final dimension and then nitrided without any significant change in dimension. Hard chrome, in contrast, requires that a barrel be made oversized to accommodate the thickness of chrome. This can reduce accuracy if the thickness of plating is not absolutely perfect.

From the manufacturer's perspective nitriding is potentially simpler and cheaper than hard chrome, with obvious benefits.

 

[tju1973]

I went with the 18" 1/7" hard chrome-- just because--- plus my dad has a crap load of 70 grain that I want to take out to try on yotes on his place....

To each his own though....I mainly liked the CMMG BB 18" due to the full length gas tube and longer sight radius...

 

[Hatterasguy]

Technology has moved on, nitride is better than chrome. Although their is nothing wrong with chrome.

Nitride with a 1:7 twist seems to be the way things are going.

 

[Maj Dad]

The TiN coating on my Hornady sizers & M14 gas piston is slicker'n' greased owl feces, and the cat's arrears. If nitriding is anywhere as useful/functional as the TiN, I want it.

 

[Aquila]

TiN, TiAlN, W DLC, etc are not "Nitriding". Nitrocarburization (salt bath or ferritic, fluidized bed, etc.) is something altogether different. It's not a plating but a surface conversion.

Missed your reply, Z-Michigan.

But there is a difference between Carbonitriding and Nitrocarburization, too.

 

[Z-Michigan]

But there is a difference between Carbonitriding and Nitrocarburization, too.

I'm all ears! And which one is (a) Tenifer and Melonite, (b) being used by companies like LWRC, DS Arms (M4 uppers), POF, etc.?

 

[Tirod]

Nitriding is what crankshafts get at the factory or in better engine shops. If you have had the bearing surfaces turned undersize, it's almost mandatory on a competition engine to re- nitride the crank.

Chroming died decades ago in that industry because of the dimensional issues. Chroming the bore of automatic rifles and carbines helps resist destruction of the throat and first few inches of rifling. It does nothing to make them more accurate other than resist the eventual deterioration of heavy fire. Target and hunting rifles, or dedicated semi auto shooters don't use or specify it as there is little to no benefit.

Nitriding does give a benefit to all shooters, and is quickly becoming the preferred method because it does not create more difficulties in manufacture.

 

[dom1104]

So are you saying, my cheapo DS Arms $250 dollar upper has the height of barrel technology?

Somehow, I find this hard to believe.

 

[Hatterasguy]

Yeah surprisingly.

 

[Z-Michigan]

So are you saying, my cheapo DS Arms $250 dollar upper has the height of barrel technology?
Somehow, I find this hard to believe.

Pretty much, yes. Although to be "the height" it would also need to be hammer forged.

Newer processes are often both better and cheaper than older processes (otherwise, why would you adopt them?). So yes, nitriding is better, and somewhat cheaper than chrome. Likewise, hammer forging is better in terms of durability and, in large production runs, also cheaper than button rifling.