Newbie question!

Looking at buying an upper and I have a choice between these 2 steels.

But I don't know what one has over the other, if anything. I tried searching the forums and got nothing. So what is the difference between these two, and are thier purposes?

Barrel of the upper I'm looking at is 16", 1/7, chome lined 5.56 chamber and bore if the info aids in a reccomendation.

Really appriciate the assistance.

bushmaster uses 4150 and its suppose to be a stronger steel

So less chance of wear and corrosion over time?

If you can actually tell a difference, please let us know.

Get chrome lining too.

Are you shooting full auto and dumping mag after mag until the barrel glows red? If not, either one will do you fine. Don't sweat this particular detail. As someone else pointed out already, get a chrome lined bbl. That's the only thing that really matters.

Quoted: Are you shooting full auto and dumping mag after mag until the barrel glows red? If not, either one will do you fine. Don't sweat this particular detail. As someone else pointed out already, get a chrome lined bbl. That's the only thing that really matters.

If I'm in that kind of situation I think I'd be pretty much fu**ed... So if it doesn't matter I guess I'll go with the 4140. If it's tempered softer maybe it will be better for long days of drills with cool down periods.

Thanks for the info guys.

This has been beat to death for sure, but here is my take...

I am sick of hearing, "you can never tell the difference between 4140 and 4150 steel bbls, so don't worry about it."

FACT: 4150 is superior to 4140.   The mil spec is 4150 or vanadium.  4140 is pushed by manufacturers because it is cheaper.  I do not buy cheap when superior parts are available for my firearms.  There is a difference.  I do heat up my bbl.  I do not care if anyone claims that I will not get the bbl hot enough to tell the difference.  FACT:  There is a difference.  I choose to use the highest quality available for my firearms.  Feel free to buy a lower quality 4140 bbl if you wish, just know what you are getting.  I choose 4150 and vanadium.

Quoted: This has been beat to death for sure, but here is my take... I am sick of hearing, "you can never tell the difference between 4140 and 4150 steel bbls, so don't worry about it." FACT: 4150 is superior to 4140.   The mil spec is 4150 or vanadium.  4140 is pushed by manufacturers because it is cheaper.  I do not buy cheap when superior parts are available for my firearms.  There is a difference.  I do heat up my bbl.  I do not care if anyone claims that I will not get the bbl hot enough to tell the difference.  FACT:  There is a difference.  I choose to use the highest quality available for my firearms.  Feel free to buy a lower quality 4140 bbl if you wish, just know what you are getting.  I choose 4150 and vanadium.

...me too.

Whats LMT use ?

Erin, Newbie post 1072????  

No reason to go with 4140, all things being equal.  If, however, you find a great deal on a particular rifle that happens to have a 4140 barrel, it could be acceptable.  If you're actually choosing between the two, go 4150

Quoted: Whats LMT use ?

LMT uses 4150.

Quoted: Quoted: Whats LMT use ? LMT uses 4150.

COLT, Bushmaster and LMT barrels are 4150... So are a couple other manufacturers, just cant remember who they are at the moment...

Quoted: FACT: 4150 is superior to 4140.   The mil spec is 4150.

+1

4150 is the best premium quality firearm steel money can buy... Although 4140 and 4150 are very similar alloys, 4150 Steel theoretically maintains its tensile strength rating at higher temperature extremes than 4140, and for this purpose is probably better suited for high volume full auto fire...

Hey gang... just checking in, busy with travel...

The numbering system is pretty easy, the first digit (4) indicates the major alloy element (molybdenum). The second digit (1) indicates the appx percentage of that material (about 1%) and the last two(40-50) are the amount of carbon in tenth of a percent (0.40% - 0.50%).

4150 is a higher carbon steel and therefore it is a little tougher, tougher on tooling is one problem and therefore it cost more to make barrels out of it. Outside of the demand for military grade barrels, where substained rates of full auto fire are normal and accuracy standards are very relaxed, you will not find many manufactueres working with 4150... keep in mind that he military does not use it for the rifle they demand the most accuracy out of, it is a good, cheap, tough, utilitarion steel that make a great service rifle barrel.

CMV is another steel that can be used by milspec, but the milspec is a generic guideline that can be dozens of different steels really, the TDP is what states specifically what steel to use for what rifle.

Let's see... 4150 is certainly not the *best* steel, CMV is better imho and both of them are mid-grade alloys that fall short of others that are available... if you want to pay the price.

None of the companies named so far here actually make barrels, they get them all from the same place or two.

The *average* user will damage the barrel form over/improper cleaning before they wear it out from shooting, 4140, 4150, or Unobtanium... does not matter. If you are the real deal door-kicking ninja, someone else pays for your stuff so it does not matter. That said, if you want to know that you have the best of the common barrels steels, without really paying any more, 4150 is probably the best way to go

That's the kind of info I was looking for! And it seems the price between the barrels is the same so I'll make sure to ask for the 4150.

And to answer your question Geohans, I'm new to the AR15 as a whole, never thought I'd get to own one that didn't take stripper clips so I didn't really look into them. With this CA Lower deal happening I decided to jump on the "black rifle bandwagon" before I got left behind. So now I'm learning everything from scratch.

Does anyone know what steel E.R. Shaw uses?

Thanks,
Matt

Quoted: Does anyone know what steel E.R. Shaw uses? Thanks, Matt

think they are 4140

Sorry, I don't know what you mean by PO. The barrel is a 16" HBAR 1 in 9 chrome lined if that makes a difference.

Thanks!

I see. Mine is most likely 4140 then.

Thanks much BravoCo

What grade of steel did Al Pacino have in...  

On the real.  It's all about (Mil-B-11595E) Chrome-Moly-Vanadium Alloy Steel *4150*

2 Words:  Sabre Defense

2 More Words:  Get Some

CMMG has 4150 barrels

Quoted: Quoted: The *average* user will damage the barrel form over/improper cleaning before they wear it out from shooting, 4140, 4150, or Unobtanium... I've had a hard time tracking down a reliable source of that stuff. I really prefer to get barrels made of Unobtanium Nitride,  but supposedly, that's so hard (to find) it's not even funny. CJ

We have been working with Unobtanium for a few years, the supplier for it is a bit of trade secret though... Now, the new alloy that is the do-all-to-end-all, but VERRRRRYYYYY hard to find is Justoutofreachium.

Quoted: What grade of steel did Al Pacino have in...   On the real.  It's all about (Mil-B-11595E) Chrome-Moly-Vanadium Alloy Steel *4150* 2 Words:  Sabre Defense 2 More Words:  Get Some

Mil-B11595E is just the spec for round bar stock ordnance steel under 2" in diameter, it can be made from any of several steels that comply with the 4150 standard or CMV. BTW 4150 is not ChroMoVan, there is no toleration of vanadium in 4150, once vanadium is added is becomes CMV.

eta: As stated, the TDP is what specifies the particular barrel steel for a certain rifle, if you check the standards for 4150, you will find it is a bit loose...

what are rock river barrels made out of?

Quoted: what are rock river barrels made out of?

they're not  made out of 4150...

Quoted: CMMG has 4150 barrels

I know...

I'm looking at one of thier 16" M4A1 SOCOM setups. Just didn't know what steel to ask for it in.

Quoted: The numbering system is pretty easy, the first digit (4) indicates the major alloy element (molybdenum). The second digit (1) indicates the appx percentage of that material (about 1%) and the last two(40-50) are the amount of carbon in tenth of a percent (0.40% - 0.50%).

Almost, the first 2 numbers indicate the basic elemental content of the alloy.  Look at the difference of 40XX (Moly) 41XX (Chrome/Moly) and 43XX (Chrome/Moly/Nickel) steels.  Whatever I just lookem up when in doubt haveBaer is having his barrels made from 4350 and I've heard of barrel makers speak highly of 4340 as a barrel material.

Quoted: Quoted: The numbering system is pretty easy, the first digit (4) indicates the major alloy element (molybdenum). The second digit (1) indicates the appx percentage of that material (about 1%) and the last two(40-50) are the amount of carbon in tenth of a percent (0.40% - 0.50%). Almost, the first 2 numbers indicate the basic elemental content of the alloy.  Look at the difference of 40XX (Moly) 41XX (Chrome/Moly) and 43XX (Chrome/Moly/Nickel) steels.  Whatever I just lookem up when in doubt But I do have a reason of bringing this up, really I do.  What do you think of bringing a bit of nickel to the party with a 43XX series steel as a barrel material?  I know that Baer is having his barrels made from 4350 and I've heard of barrel makers speak highly of 4340 as a barrel material.

Across the board, the AISI and SAE numbering system calls out things a little differently, then there is UNS... To cover all of these would take a lot more time and space than is available.

However, you are correct for some alloys, but the topic was 41XX series ChroMo and the description that I stated is directly from the Aerospace Materials/Alloy manual... 0.95% Cr 0.30% Mo and the Carbon percentage is given by the last two digits. I appologize however that I said moly as the major element, when I should have said Chromium...

43XX series would certainley be a worthy choice (hammer forged?), as is 61XX

Quoted: 43XX series would certainley be a worthy choice (hammer forged?), as is 61XX

Gale McMillan is one of the guys that will always mention 4340 and I know the McMillan barrels were button riffled.  I'm pretty sure the Baer barrels are made by Kart and I don't know what process he uses (my guess would be buttoned riffled).  I'm guessing it would be a pretty damn hard alloy to use a cut riffling process with the added nickel.  Hell, deep hole drilling and reaming the smaller holes for the button riffling process is probably why nobody uses it (wouldn't matter as much on pistol barrels though).

6150 is interesting, a bit more thermally conductive and has all the strength of the other two alloys mentioned.  Good stuff, thanks.

Quoted: Quoted: 43XX series would certainley be a worthy choice (hammer forged?), as is 61XX Gale McMillan is one of the guys that will always mention 4340 and I know the McMillan barrels were button riffled.  I'm pretty sure the Baer barrels are made by Kart and I don't know what process he uses (my guess would be buttoned riffled).  I'm guessing it would be a pretty damn hard alloy to use a cut riffling process with the added nickel.  Hell, deep hole drilling and reaming the smaller holes for the button riffling process is probably why nobody uses it (wouldn't matter as much on pistol barrels though). 6150 is interesting, a bit more thermally conductive and has all the strength of the other two alloys mentioned.  Good stuff, thanks.

You hit it on the head, the better the choice of steel for a barrel, the harder it is to make it into a barrel... I know that some exotic alloys have been used, but that involves drawing and drilling, tempering, straightening, normalizing, stress releiving, blah, blah, blah...

Then, you are left with getting the rifling and chamber in! There is the option of EDMing the chamber and chemically etching the rifling? I am sure you will find that some of these harder/tougher materials are used in shorter pistol barrels for the reasons you mention... here is a thought, 17-4PH

Quoted: here is a thought, 17-4PH hr

That's just wrong, 16% Cr and 4% Ni, well at least if you ever finish the barrel it should last forever hock.gif .  Well it may be the thing for the top IPSC/USPSA shooters but I'd sure cost enough (both in material cost and machine time).  I guess 17-4PH would end all arguments of what will last longer a SS or a CM barrel hat).  Have you heard of anybody messing around with EDM chambering prior to June 9, 2003?