How much difference will this really make. I am building my own AR and I am battling with the barrel idea. Part of me tells me to go with a chrome lined one for durability and cleaning. The other side says take the cheaper road and possibly get better accuracy. I mean will I need to take more time with a chromemoly barrel? Not give it as much abuse. I know the chrome is milspec and better for armed forces fighting in a wide range of climates. Does it make a big difference if I don't have one. Come on guys either talk me into one or the other cause I can't make a decision. Thanks

without knowing your general use and life expectation....................

barrel config?
target, optics, range, situation?
spraying 30rnders?
budget?

Dont chance it go chrome and you will get your money back in the extra barrel life in the long run.

Well I am not building a match rifle, and I am not building a rifle to shoot every weekend. But ocassionally I will put a lot of rounds through it, I may not clean it after every use. I want a rifle that I can ensure is going to not foul up and fail. I say this cause I have always had chrome, but there are several manaufacturers out there who sell ChromeMoly?

"Chrome moly" steel is just ordinary barrel steel.  All rifle barrels are made of it (or stainless).  It's nothing special.

The only reason to advertise "chrome moly" is to try to make folks think it's chrome bore.  If you don't see "chrome bore" walk away.

You don't get match accuracy from cheap "chrome moly" barrels or from production run barrels of any type.  From match chrome moly barrels, sure, but not the barrels you're looking at.  Chrome bore is not less accurate if you compare apples and apples.  Non-chromed match barrels are more accurate, with match ammunition, than production run chrome bores.  

Since a barrel like a Bushmaster chrome bore will bench shoot under 1" at 100 meters it'll shoot better than you can.

-- Chuck

what are your suggestions on stainless versus chrome lined

Stainless is for match barrels.

Stainless steel isn't.  Many if not most alloys will rust.  In match barrels the maker is more important then the material.

For duty or SHTF barrels give me chrome bore every time.  If I could find a way to have my M1 Rifle's barrel chrome bored I'd consider it.  

-- Chuck

If you don't see "chrome bore" walk away.

Or chrome-LINED.  Same thing.

Does this mean that I should have gone w/ the Varminter special that had the Stainless Steel barrel instead of my just plain Varminter?  Bushmaster said that the 24" Varminter is the most accurate out of the box rifle they make.

I remeber seeing a program on the history channel that talked about the M-16 when it was first introduced in Vietnam. It had a lot of problems and they attributed this to the barrel and reciever not being chrome lined. Is there any truth in this statment? Chrome helps keep the fouling of the rifle down when you may not be able to steadily clean your rifle?

Yes and Yes

For anything but a tack driving bench gun...

"Go chrome or go home x2!"

The problems in 1966-67 with the XM16E1 were caused by troops not cleaning their rifles and the failure of their leadership to insist they cleaned them.  If you read any reports about rifle problems keep in mind this was primarily a leadership problem!  Any company commander who allowed these problems to occur was a commander in name only.

My company had these same raw steel barreled XM16E1 rifles in 1968 -- in fact they'd been in the field a couple of years -- and had none of these problems.  Reason?  We cleaned our rifles daily and our chain of command was rabid about it.

Chrome bore eased the amount of effort needed to accomplish this.  All you gotta do these days is drop a bore snake down the barrel daily and you're good to go.

The M14 had a chrome bore from the git go, as did the SKS45 and AK47/AKM.

-- Chuck

Is this guy refering to a chrome LINED barrel or the chrome barrel itself? The difference is chrome moly(41xx - for the rest of this post xx would denotate carbon content in the steel usually 40 in this case) and Chromium Steel(5xxx - for here on 51xx or 52xx is the difference between low and medium content chrome again the xx is for carbon).

Chromium Molybedenum(41xx)- Is principly a steel with molybdenum as a primary alloying element. It's widely used in the aircraft industry and many other places (like high performance auto). This steel is easily welded and will produce a FINE grain structured steel. This fine grain structure increases the strength of the steel and I imagine would make it easy to make a more accurate weapon from(this is speculation on my part, not sure). This steel behaves well at elvated temperatures and pretty much gets the best of molybdenum traits and chromium traits.

Chromium traits (5xxx) are INCREASED wear resistance, increased toughness, hardness, increased responsiveness to heat treatment, and increased corrosion resistance.

The real debate in my mind between 4140 and whatever 5xxx is used is does my barrel need the fine grain structure and extra strength? Am I willing to sacrifice some barrel life for some accuracy? I doubt the barrel life you trade is GREAT but nonetheless it's a consideration. If it's a 51xx level chromium steel then I'd probably stick to 4140 if it's 52xx level then I would start thinking how much I want that barrel life.

Anyone mind telling me the typical 5xxx used in milspec barrels?

Mil-Spec barels use 4150 Chrome/moly steel with a chrome lining.

Most of the AR makers use 4140 (only Bushmaster & Colt use the mil-spec 4150).

The question is whether the persone should get a bare (4140) barrel or a chrome lined one.

I am one of those in the 'Go Chrome or Go Home' camp.  Preferably with a Bushmaster barrel of 4150.

This is a great question since I have the same dilema.  I was told by DPMS that the Stainless bull fluted would do 1/8" 10 shot groups at 100yrd with factory match ammo.  I don't know if that was in a vise or not.  I saw one of those in person and the barrel was huge.  Seemed a bit disproportionatly weighted.  The BM Varminter seems hugely popular and is also touted as highly accurate...sub 1" groups at 100yrd and many say better.  I also read SS can explode in cold temps?  Any truth?  So far consensus:  Buy the Bushmaster for all around but the DPMS for bench applications.
WARNING: Just spitting back what I've read.  No practical experience to speak from.  I'll be buying my first AR type in a week or so but haven't decided yet as I still don't have a clear picture of what is the more accurate rifle.  
T

My main point for asking the question wasn't really from a bench shooting format. I don't shoot that way nor am I looking for a rifle to do that with. Most of my shooting is at a range that I can place targets from 50-300m and then randomly take shots at them (there metal and they make a ding and move). My main point was will the Chrome lined barrel offer me greater durability and reliability. I would rather be able to count on a rifle that is accurate yes, but reliable first and foremost. I take and use a boresnake at the range anyway. I just wanted to know if it would be cheaper in the long run to go with a chrome barrel vs a chromemoly or stainless barrel?

My main point for asking the question wasn't really from a bench shooting format. I don't shoot that way nor am I looking for a rifle to do that with. Most of my shooting is at a range that I can place targets from 50-300m and then randomly take shots at them (there metal and they make a ding and move). My main point was will the Chrome lined barrel offer me greater durability and reliability. I would rather be able to count on a rifle that is accurate yes, but reliable first and foremost. I take and use a boresnake at the range anyway. I just wanted to know if it would be cheaper in the long run to go with a chrome barrel vs a chromemoly or stainless barrel?

Also and God forbide a SHTF situation and I couldn't clean or wasn't thinking about cleaning my rifle every single day, would the chrome be better and a regular barrel?

Chrome bore is the best all around barrel available for these rifles.  These have chrome moly steel barrels.  Colt's or Bushmaster are your choices.  Not sure what DPMS is trying to sell you.

-- Chuck

exterm223,
You seem to have a good grasp of metalurgy, so I'll toss you this question.  What are the differences between the 4140 and 4150 steels?  Milspec is 4150 and I'm sure it's better, but in what ways?  Heat tolerance, raw strength, wear?

edblevi,
For a general purpose rifle chrome-lined is preferable to an unlined barrel.  Easier to clean (and better if you can't), and lasts longer.  It won't be quite as accurate as an unlined barrel because they can't control the thickness of the plating completely so the bore is less uniform.  That's why the super-duper match guns aren't lined.  For the use you describe, you won't be able to tell the difference.

Mike, Well I'll start off saying your right. 4150 is considered a better steel alloy for this use. The last two numbers The 40 or 50 in this case show the percentage of carbon in the alloy. 4140 should have 0.40 percent carbon content. 4150 should have 0.50 percent carbon content. Make sense so far? Good. Since we know the only real difference is carbon, lets look at what it does in a steel alloy.

As carbon content increases, so does the tensile strength of the material and the hardness. The higher the carbon content, the better the steel will respond to heat treatment and really the only notable drawback is a decrease in malleability.

The difference between 4150 and 4140 is honestly not that big of a deal. If you have the option and don;t mind the few extra buck I'd get the 4150 but 4140 really will leave you no worse off. The chrome lining would be the only semi-important difference in my humble opinion. Good luck selecting a barrel, ohh and may I suggest you do a tiny bit of reading on ferrous metals and non-ferrous metals as it will make choices in knives, components, and various things a bit more easy.

Chrome Lined man Chrome Lined. Buy the Chrome Lined barrel . At most your talking $30 extra. Come on man $30 extra wont break you . Chrome Lined barrel is the choice for you .. Hows that ! Did we talk you into it . BTW When your done this project I'll do my best to try and talk you into giving it too me  

SaFe ShOoTiNg
Jerry

Quoted: Chrome bore is the best all around barrel available for these rifles.  These have chrome moly steel barrels.  Colt's or Bushmaster are your choices.  Not sure what DPMS is trying to sell you. You have convinced me, I am sending in my Bushy receiver with stainless barrel for a new chrome-John. -- Chuck