Author Topic: The VZ2008 barrel: Who's the maker and how's the quality?  (Read 6040 times)

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Offline parabellum

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The VZ2008 barrel: Who's the maker and how's the quality?
« on: March 06, 2011, 10:29:59 AM »
More to the point, how's the quality compared to a typical surplus vz58 barrel?

Offline rocinante

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #1 on: March 06, 2011, 10:52:52 AM »
Green Mountain makes the barrel. AFAIK nobody has shot the barrel out yet or complains it is in inherently fubar or inaccurate. 

Offline armoredman

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #2 on: March 06, 2011, 12:18:37 PM »
I haven't heard anything bad about the barrels or Green Mountian. The barrels have to be home grown nowadays as the "parts kits" that come in are now restricted from imported barrels, thank you, fed.gov.

Offline parabellum

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #3 on: March 06, 2011, 12:30:28 PM »
Well, as I understand it, Century contracted for new, legal-length barrels so that it would not be necessary to add an extension to the original sub-16" vz58 barrel.

Offline jmp8927

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #4 on: March 06, 2011, 12:39:27 PM »
Green Mountain has a very good reputation for making high quality barrels. I have a Green Mountain barrel for my Ruger 10/22 and it's been great. As said before, they're deliberately made just over 16 inches so you can put any kind of muzzle attachment on it and not have to permanently attach it to be legal.

Offline parabellum

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #5 on: March 06, 2011, 12:59:42 PM »
Thanks for the information. Is there any difference in twist rate between the two barrels?

Offline ObiWanBonJovi

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #6 on: March 07, 2011, 08:21:33 PM »
they are green mountain barrels and non chrome lined.  Accuracy seems to be fine, but the barrels are made of 4140 and hardened to 30-35 rockwell.  IMHO too soft for a barrel.  I wouldn't expect a life of more than a few k before accuracy starts to degrade.

Offline rocinante

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #7 on: March 07, 2011, 09:11:14 PM »
Quote
but the barrels are made of 4140 and hardened to 30-35 rockwell.

that is pretty specific info. Where did you hear or read that?

Offline parabellum

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #8 on: March 07, 2011, 09:52:44 PM »

Quote
but the barrels are made of 4140 and hardened to 30-35 rockwell.

that is pretty specific info. Where did you hear or read that?

I'm kinda curious about that myself.

BTW, anyone know about the twist rate?

Offline armoredman

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #9 on: March 07, 2011, 10:22:59 PM »
Obiwanbonjovi makes some vz-58 parts, (nice gas piston rods and steel triggers, all marked "made in USA" for 922r compliance), so he probably does have an ear to the ground in those circles. I personally know little to nothing about Green Mountain except that I can't remember hearing anything good or bad.

Offline rocinante

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #10 on: March 08, 2011, 04:59:59 AM »
Obiwanbonjovi makes some vz-58 parts, (nice gas piston rods and steel triggers, all marked "made in USA" for 922r compliance), so he probably does have an ear to the ground in those circles.

If he knows something credible I wish he would share. There are lots of drive by pot shots at the rifles but oddly very little concrete info on them. I have looked and not found any real info on who does the finish and assembly much less a detail like Obiwan just did a hit and run with.  Inquiring minds want to know you know.


 

Offline Nova-Wake

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #11 on: March 08, 2011, 06:51:32 AM »
I trust his word he has nothing to gain by making anything up, He has to be one of the most knowledgeable people we have on the forum. He is a guru on these things. But that is why i bought a czechpoint for the military barrel.

Offline rocinante

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #12 on: March 08, 2011, 10:43:45 AM »
If the barrel is 4140 chrome moly with a RC range of 30-35 it sounds like they did it within standard range, not too soft or hard. If it is any harder it gets into brittle range which could turn the barrel into a fragmentation grenade instead of bulge under too much pressure.  

I know absolutely nothing about this stuff but google is my guide :) Comments from several sources.

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Most barrels for use on hunting rifles and in military firearms are made from a high alloy Chrome Molybdenum steel of the sort used in high stress components such as truck axles, conrods and such. In the United States these steels are designated as 4140, 4150 and 4340 types

(I had an unfortunate hard slam encounter with a curb and bent an axle shaft in my mustang. Wonder what grade of steel it is? Destroyed the aluminum mag shaving a inch thick and 3 foot long blade off the rim. )

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Rc 32, the upper end of the hardness range that still readily permits the types of machining operations involved in making barrels.

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Elasticity must be maintained in gun barrels, and the range of 26-32 Rc (Rockwell C scale) hardness has been determined as the appropriate, safe tradeoff

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Tensile strength and hardness affect barrel performance. Tensile strength is the force required to break a steel rod one inch in cross-sectional area by pulling at both ends. Generally, hardening steel increases its tensile strength. But a tensile rating of 100,000 pounds for a rifle barrel is worthless if the steel is so hard it's brittle. A hardness of 25 to 32 on the Rockwell C scale has proven a useful compromise.

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Generally speaking, the tensile strength of a steel can be increased by hardening it. But as the hardness is increased, so the steel becomes more brittle and it becomes more susceptible to fracturing from a hard knock or sharp impact - or setting off a small explosion inside a tube of the stuff! A trade off must therefore be made of tensile strength against impact strength and for barrel steel the resultant hardness settled on is usually between 25 and 32 on the Rockwell C scale.

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Quick summary of checks I have made over the years:

Older vintages of military Mauser barrels and early 1903 Springfield .30/06 manganese steel barrels around Rc 10.

Later Springfield .30/06 barrels made from what P.O. Ackley said was "WD4140," WD meaning "War Department", was around Rc17, the average hardness of "normalized," ie, air cooled 4140 steel.

The majority of commercial barrels from Winchester, Remington, Ruger, etc. tested around Rc 24-26, while at the time I tested them, the Savage 110 barrels were right up there at around Rc 30-32.

Shilen barrels at the time were Rc 19 while Douglas was around Rc 25.

Current Shilen barrels run around Rc 29-30.

Most 416 stainless rifle barrels are around Rc 20, +/-.

As you can see, barrel steel hardnesses range all over the planet, over the entire hardness range from dead soft annealed up through about Rc 32, the upper end of the hardness range that still readily permits the types of machining operations involved in making barrels.

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an opinion supporting obiwan position

The 4140 used for these barrels have a hardness of Rc 26-32. This is a wide range, thus why some last longer than others. Chromelining has a Rc ~70 and a Combloc barrel Rc ~40 (usually). If these barrels were Rc 30 and chromelined = GTG, but their not.

« Last Edit: March 08, 2011, 10:59:35 AM by rocinante »

Offline kiev88cm

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #13 on: March 08, 2011, 12:33:10 PM »
   I would like to hear from someone who has put 1000 rounds through the Green Mountain ( Century ) barrel and see  if accuracy has been lost.  These guns were designed originally with chrome lined bores....chrome is much more resistant to wear than steel. 

Offline armoredman

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Re: The VZ2008 barrel: Who's the maker and how's the quality?
« Reply #14 on: March 08, 2011, 12:59:32 PM »
I spoke to an SOT I know out here who said he like Green Mountain's product.

 

anything