So is vanadium alloy and chrome moly the same thing?  I ask because I was looking at the sabre defence catalog and it seems their barrels are made of this metal.

Thanks guys...

Quoted: So is vanadium alloy and chrome moly the same thing?  I ask because I was looking at the sabre defence catalog and it seems their barrels are made of this metal. Thanks guys...

Nope... molybdenum alloy steels are 4XXX series steels and vandium alloy steels are 6XXX series. The federal specifications for aerospace steels was just updated this summer (july 05) and specifies ordnance steel as 4150 (which has no vanadium content).

so does that make the chrome molly stronger?  I know nothing about metals obviously...

okay, so i know 4150 is stronger than 4140, but where does this vanadium stuff fall?  Would it be bellow 4140, the same as 4140, or slightly stronger?  

Both of my midlengths are 4140 from RRA.  4140 is good enough for me (4150 would be good too obviously), but I want gov profile, and I don't want to have to send my barrel to ADCO everytime to get some weight shed from the RRA barrels.  I DON'T want a barrel that is inferior to 4140.

The chrome vanadium is supposed to be SUPERIOR to 4150. This is what makers of vanadium alloy barrels will tell you anyway. This is what LMT and Saber barrels are made of I believe.

Quoted: The chrome vanadium is supposed to be SUPERIOR to 4150. This is what makers of vanadium alloy barrels will tell you anyway. This is what LMT and Saber barrels are made of I believe.

to my knowledge, LMT uses 4150.  

edited cause I found the answer after looking most of the day.

This was what i found after a days worth of research:

Description of Bushmasters "DCM" Competition Rifle:

The 20" Bushmaster Extra Heavy Competition Barrel is a full 1" diameter under the handguard and is available in 1 x 8" precision rifling. They are machined from Chrome Moly Vanadium barrel steel and are hardened to Rockwell C26 to 32 - superior to stainless barrels!

This is what Bushy had to say about their barrels:

We machine our barrels from the best grade Chrome-Moly Vanadium Steel - to military specification - and we offer more than 85 different configurations Our match heavy barrels are full diameter from barrel nut to front sight base to improve heat dissipation and decreases barrel whip in rapid fire. We rifle almost all our barrels 1 turn in 9". The Gov't. originally specified a 1 in 7" twist but we have found that the 1 in 9" twist gives the best results with the widest range of ammunition, and will stabilize most bullets up to 72 grains.

And this is what I found on Armalite:

ArmaLite offers barrels made of stainless steel, 4140 chrome moly, or Mil spec chrome lined. Our chrome lined Mil Spec barrels are made of tough chrome-moly-vanadium barrel steel and are rifled at 1 turn in 9 inches ... far superior to the 1 turn in 7 inch twist government barrel.

Sabre Defence catalog begins with telling us about themselves.  Towards the end, It says that their barrels are Chrome-Moly-Vanadium, but not cheap 4140, so I'm guessing 4150.  If only I would have read from the beginning, instead of from the middle...

Chrome-Moly-Vanadium steel is the current milspec material for M16 barrels and 4150 is the milspec material for M14 and Garand barrels.  Cr-Mo-Va is the same as 4150 except for a small amount of vanadium added to improve high temperature (full auto) strength.  Unfortunately neither it or 4150 are commercially produced by steel mills so that's why 4140 barrels are a lot more common.

4150 is absolutely commericially produced by steel mills. I purchase it often for personal projects. 4140 is easier to machine -- I imagine this is why many barrel manufactures choose it over 4150, which is really a superior steel for barrels.

4150 has a higher carbon content than 4140. In industry, 4140 is used as a general purpose alloy steel, while 4150 is used in applications where its increased wear-resistance is desirable. "Chrome-moly-vandium" results from adding vandium to the existing alloy structure of either of these types of chrome moly steel, but in most cases chome-moly-vandium is 4150 plus vandium.

4140 vs 4150 should only be a consideration in "crhrome-moly" barrels and not chrome lined.  

Quoted: Chrome-Moly-Vanadium steel is the current milspec material for M16 barrels and 4150 is the milspec material for M14 and Garand barrels.  Cr-Mo-Va is the same as 4150 except for a small amount of vanadium added to improve high temperature (full auto) strength.  Unfortunately neither it or 4150 are commercially produced by steel mills so that's why 4140 barrels are a lot more common.

Interesting... I am on the road and can not get to the books, but I was not aware the CrMoV was being speced for the M16 (I would have guessed it was for CIWS and that sort of thing...), but you learn something new everyday.

I know that the current fedspec still calls 4150 the ordnance steel for smaller barrels, what publication is it that lists CrMoV as spec for the M16?

Last itme I looked at the spec is was EITHER:

4150 (which has no Vanadium)

OR

Chrome-Vanadium alloy (as an alternative)

Have never heard of spec for 4150 Vanadium as a required spec but do not see why it would not be disallowed.

Isn't Denny's operator barrel described as 4150 with added Vanadium content??

Quoted: Quoted: 4140 vs 4150 should only be a consideration in "crhrome-moly" barrels and not chrome lined. I'm not sure what this confusing statement is supposed to mean. Both 4140 and 4150 are chrome-moly steel alloys.  Both can be chrome-lined (i.e., the bore chrome-plated), but chrome-lining has nothing to do with the properties of the barrel steel. 4150 steel has two very real advantages over 4140: increased wear resistance and the ability to retain its structural strength at higher tempertures.  The downside is the higher cost and increased difficulty of machining. Chrome-lining a barrel is done to increase corrosion resistance, to make cleaning easier, and to improve barrel lifespan. -Troy

Im well aware of that IM saying that wear resistance isnt really that much of a problem in chrome lined barrels because the bullet doesnt contact the steel.

Sabre also makes barrels for the .50 M2; just FYI

Federson Barrels in Knoxville TN uses a high vanadium content in the barrels he makes for Barrett. When diamond lapped, the barrels we cross sectioned had a mirror finish on the lands and grooves.

Troy

Thanks for the informative posts , I have been waiting for some one to come along and explain the whole 4140/4150 thing . I have tried to get answers in other threads but wind up getting unintelligent rambling like because Colt says so . Thanks for taking time to bring me up to speed !

4140

4150

Another question, what about those special purpose m16 being built with Stainless barrels?  What is better 4140 or SS steel?

LMT uses Vanadium on all there 1/7 twist bbls

Excellent thread!

I found somemore reference to the CMoV barrels on the archive server.  The thread is about the Sabre barrels and on page 7 Tweak actually found the Mil-B specs that discusses the differnt barrel steels that the military prefers.

It also looks like the CMoV barrels are also called Mil-B-11595E steel.

archive.ar15.com/forums/topic.html?b=3&f=118&t=235033&page=7

This excellent discussion on rifle barrel steel has me thinking.
Just for curisoity's sake,  I'd like to ask - -

Colt rifles, prior to the '94 AWB, what alloy did they make their barrels from?

Thanks!

Well, since I check this site more tha I check my e-mail, I just got an e-mail from Sabre Defence that anwered a couple of questions of mine.  I think you all can guess the questions by reading what they had to say:

The alloy we use is what the Government calls for in  Machine Gun Barrels it is a tougher material than standard 4150 and way better than 4140.
We use both types of barrel extensions the 1:7 mid-length have the m4 type ramps and the 1:9 mid-length have std rifle ramps.
Thanks for your interest in Sabre Products.

Looks like from everything said in this thread and what Sabre had to say, I'll prolly be buying the 1:9 Midlength barrel from them...