Chromed or 'lined' AR barrels - or not - Page 2

Sweet Shooter · November 13, 2012, 12:37 PM

@ Skans...

I agree. I'm not seeing a loss of accuracy, and in fact have been surprised seeing improvements.

A well made barrel is a well made barrel. Of course there's little hope for a dogs leg of a barrel that has subsequently been preserved in that state by chrome lining.
-SS-

stubbicatt · November 13, 2012, 12:38 PM

There are advantages to the chrome lined barrel. True. I wonder though, why does the .mil obtain "nitrided" or "melonite" M2 50 cal barrels then? From what I have read elsewhere that the melonite process yields a more wear resistant barrel than chrome.

I do not know whether it is similarly resistant to rust and corrosion, however.

Skans · November 13, 2012, 02:49 PM

Because chrome lining barrels involves toxic substances and EPA restrictions makes this process prohibitive, unless you are doing very large orders.

In fact the availability of chrome lined barrels is one of the major advantages to owing an AR, or even an AK. Now, if they would only make AR receivers in steel and gas pistons for .308, they'd almost be as good as a FAL.

johnwilliamson062 · November 13, 2012, 09:45 PM

Melonite trumps chrome for durability and corrosion resistance. I am surprised by claims of accuracy. Nitrided guns are noticeably textured when compared to blued, chrome, stainless. I can't imagine that texture led to a decrease in accuracy. I have nothing scientific backing that belief though.

Metal god · November 13, 2012, 10:13 PM

Quote:

Melonite trumps chrome for durability and corrosion resistance.

Is this a general statement as to coating metals as a hole ? Or are you being spesific to chrome lining the bore , chamber , BCG ,and gas key . Like I said in a post earlier I do not know much about the process or how it compares .

arizona98tj · November 13, 2012, 10:39 PM

If you have a little time, do some research on the net....you'll find info about it.

Metal god · November 13, 2012, 11:35 PM

Did a little research and I do mean a little . This is what I found so far .

The MELONITE and QPQ process increases fatigue strength about 100% on notched components made from unalloyed steel parts and about 30-80% on parts made of alloyed steels.( like a barrel ) The hardness is maintained up to about 930�F and extends the surface life of steel tools and components exposed to heat.

This study shows how hot the external temp of a M4 barrel can get ( page 24 ). Well over 1,000 degrees with very high rates of fire and teeters right around the 900 degrees mark at moderately high fire rates . Im sure the actual bore gets much hotter then the 930 degrees the melonite is designed to withstand .What does this mean to 99.9 % of us ? Most likely nothing .
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA019649

Now for chrome lining I'll be back

johnwilliamson062 · November 16, 2012, 02:06 AM

Nitriding is an incredible firearm finish. I am a little bit crazy about finishes. IMO nitriding is way beyond anything else out there on every measure of utility. It is used heavily in Europe. To get a gun in the US with it you have to look hard or buy a European gun. I don't think it is even that expensive to do.

It is the ugliest finish though. Look at a Glock slide after it is holstered just a few times. Where it rubs the color changes. Drives some people crazy.

Skans · November 16, 2012, 08:08 AM

Quote:

It is the ugliest finish though. Look at a Glock slide after it is holstered just a few times.

You think that makes a Glock ugly!!!

November 13, 2012, 10:39 PM	#31
arizona98tj Senior Member Join Date: December 10, 2007 Location: Arizona Posts: 980	If you have a little time, do some research on the net....you'll find info about it. __________________ stu-offroad.com Largest Jeep TJ project site on the web! (now with guns)

November 13, 2012, 11:35 PM	#32
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,876	Did a little research and I do mean a little . This is what I found so far . The MELONITE and QPQ process increases fatigue strength about 100% on notched components made from unalloyed steel parts and about 30-80% on parts made of alloyed steels.( like a barrel ) The hardness is maintained up to about 930�F and extends the surface life of steel tools and components exposed to heat. This study shows how hot the external temp of a M4 barrel can get ( page 24 ). Well over 1,000 degrees with very high rates of fire and teeters right around the 900 degrees mark at moderately high fire rates . Im sure the actual bore gets much hotter then the 930 degrees the melonite is designed to withstand .What does this mean to 99.9 % of us ? Most likely nothing . http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA019649 Now for chrome lining I'll be back __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .

November 13, 2012, 12:37 PM	#26
Sweet Shooter Senior Member Join Date: June 17, 2011 Posts: 672	@ Skans... I agree. I'm not seeing a loss of accuracy, and in fact have been surprised seeing improvements. A well made barrel is a well made barrel. Of course there's little hope for a dogs leg of a barrel that has subsequently been preserved in that state by chrome lining. -SS-

November 13, 2012, 12:38 PM	#27
stubbicatt Senior Member Join Date: September 15, 2007 Posts: 1,707	There are advantages to the chrome lined barrel. True. I wonder though, why does the .mil obtain "nitrided" or "melonite" M2 50 cal barrels then? From what I have read elsewhere that the melonite process yields a more wear resistant barrel than chrome. I do not know whether it is similarly resistant to rust and corrosion, however.

November 13, 2012, 02:49 PM	#28
Skans Senior Member Join Date: November 20, 2008 Posts: 11,132	Because chrome lining barrels involves toxic substances and EPA restrictions makes this process prohibitive, unless you are doing very large orders. In fact the availability of chrome lined barrels is one of the major advantages to owing an AR, or even an AK. Now, if they would only make AR receivers in steel and gas pistons for .308, they'd almost be as good as a FAL.

November 13, 2012, 09:45 PM	#29
johnwilliamson062 Junior member Join Date: May 16, 2008 Posts: 9,995	Melonite trumps chrome for durability and corrosion resistance. I am surprised by claims of accuracy. Nitrided guns are noticeably textured when compared to blued, chrome, stainless. I can't imagine that texture led to a decrease in accuracy. I have nothing scientific backing that belief though.

November 16, 2012, 02:06 AM	#33
johnwilliamson062 Junior member Join Date: May 16, 2008 Posts: 9,995	Nitriding is an incredible firearm finish. I am a little bit crazy about finishes. IMO nitriding is way beyond anything else out there on every measure of utility. It is used heavily in Europe. To get a gun in the US with it you have to look hard or buy a European gun. I don't think it is even that expensive to do. It is the ugliest finish though. Look at a Glock slide after it is holstered just a few times. Where it rubs the color changes. Drives some people crazy.