I hear carbon fiber barrels tend to get burned out much faster than all steel barrels.
<br> It seems they don't feel hot - the carbon wrap doesn't transfer heat well - so the owners shoot them more often and don't allow them to cool. Since they stay hot longer, says the theory, and get shot more in the same time frame, they get burned out much faster. Sometimes in just one PD shoot.
<br> Anybody have anything like this happen to them ? E

Don't know a thing about carbon barrels but I know it isn't hard to shoot out ANY barrel in a hot prairie dog town. I know a few who have done just that. Which is why I like to take four rifles. Few are the times that I could have all four too hot to shoot at the same time.

although i've never done it, a friend of mine fried a 243 and a 22-250 in one weekend on a dog town... steel barrels, though.. don't have the resources to run experiments like that on carbon barrels.
<br>
<br>

I think the crucial factor would be WHOSE carbon-fiber barrels you're shooting. Most don't dissipate heat well, because of the usual nature of the carbon fibers. The company that winds one brand (Advanced Barrel Systems) is patenting a simple process that utilizes the fibers' own idiosyncrasies to increase the dissipation of heat.
<br>
<br>I can't say more. We'll soon, no doubt, hear from carbonman with "the word" about this. He knows all the grand and fine details of this new process and its lab- and field-tested results.

E,
<br>First I apologize for the essay that follows, however, this question can�t be addressed briefly. Most carbon barrels on the market use fiber and resin that do insulate heat. The concentration of heat at the thin wall liner does accelerate wear and will fry in less time than a conventional barrel.
<br>First some points regarding properties of different kinds of carbon fiber.
<br>
<br>There are 2 major categories of carbon fiber.
<br>
<br>The polymerization of acrylonitrile yields PAN type fiber. This type is common to fishing poles, golf club shafts and most carbon fiber rifle barrels.
<br>Characteristics are medium stiffness and low coefficiency of thermal conduction. This fiber also has a fairly neutral coefficient of thermal expansion.
<br>
<br>The polymerization of coal tar pitch or mesophase coal tar pitch yields Pitch type fiber. In it�s finer grades it is often referred to as graphitic carbon fiber. This fiber is more commonly used in aerospace applications and is 3-30 times more costly than PAN fiber. Characteristics include super high stiffness (modulus) and extraordinary coefficient of thermal conduction. On the downside, pitch fiber has a negative coefficient of thermal expansion. (Heat it and it shrinks!)
<br>
<br>Bear in mind that carbon fiber conducts heat in the same manner that fiber optic cable conducts light. It tends to follow the fibers and unless a radical approach is used, it will not cross from fiber to fiber.
<br>
<br>416R stainless gun barrels conduct heat at about 16 watts per meter-Kelvin (w/ms*K). PAN fiber of different grades conducts heat at 14-20 w/ms*K. Pitch based fibers conduct heat at 140 � 800 w/ms*K. Pitch fiber will carry a ton of heat at super high speeds.
<br>
<br>Traditionally carbon barrels were made to be light. No more, no less. The buzzwords of �heat dissipation� could be construed as marketing. The fiber and resin mixtures in use were garden-variety PAN fibers and low temp boat repair type resins. None of these work very well. Witness Remington�s withdrawal of their carbon offering, Browning too. The market didn�t want to pay $1000 for a barrel that didn�t last longer than conventional or group at less than 2�. http://www.galleryofguns.com/Shootingtimes/Articles/DisplayArticles.asp?ID=1114
<br>
<br>I am a prairie dog hunter that has burned many barrels in a week on good towns. When I entered the aerospace composites field I began the research and engineering to develop the high heat management fiber application in small arms.
<br>
<br>What I have discovered is a way to use the high heat transport graphitic pitch fiber to conduct heat through the wall of the carbon fiber barrel. I use a special filament winding technique and a duplex fiber content to maximize the heat transfer and eliminate the incredible shrinking carbon problem that leads to wandering zero points and 2+� groups. The resin is tough, heat resistant and has a vibration-dampening component.
<br>http://www.alltel.net/~mdegerness/pr01.htm has some charts with the 3rd party thermal testing data.
<br>
<br>Here�s a comment from a shooter testing the full auto M4 �
<br>�This is going to be the neatest thing since the thong bikini.
<br>Harder than woodpecker lips and it sheds heat at an amazing rate.
<br>After 8 minutes you can hold the barrel easily. 5 minutes after several
<br>strings of full auto it was below the boiling point for spit!!�
<br>
<br>(I don't believe the spit was a formal testing technique. I think the shooter was having so much fun with this suppressed M4 that he began drooling!)
<br>
<br>The whole idea behind my barrel development was a barrel that manages heat, shoots small groups and is priced reasonably.
<br>
<br>

Go Mike!
<br>
<br>Rick

I love it. Do keep us informed Mike. I'm always interested in an edge. E

E brings up an interesting point about the carbon wrap barrel not feeling hot so it gets shot more and burns the throat out quicker.
<br>
<br>What about a heavy barreled varmint or big game rifle? Wouldn't the same be true of an all metal barrel? The barrel doesn't "feel" hot so it keeps getting shot and the throat gets fried much quicker???

A heavy barrel has more metal, and surface area, to spread out the heat of each round. Therefore the throat temperature would be lower assuming some cooling time.
<br> However, I would think in applications like a machine gun, the weight of the barrel wouldn't make much difference. E

How's about a carbon fiber wrapped S/S barrel,that is chrome lined?
<br>
<br>I could get the hang of low maintenance and something nearly impervious to all abuses.
<br>
<br>Thoughts?...............

"A heavy barrel has more metal, and surface area, to spread out the heat of each round."
<br>
<br>That's not the way it works, Amigo. The heavier barrel has a LOWER ratio of surface area to the volume of its steel, therefore it absorbs heat and dissipates it SLOWER than a lighter barrel does. This is a basic principle of physics, and I've calculated the surface-to-volume ratios for different weights of barrel, and they vary exactly this way, in every comparison.

Stick,
<br>You are way on the right track. We have a bore coating in development that has gone 10,000 rounds and still looks and shoots like scary new. I wish I owned the coating process. I'm in cahoots with the folks that do and will report back the final testing results of the coated and carbon fibered barrels.
<br>
<br>Chrome is about 972 on the Knoop hardness scale. The process of chroming a bore leaves a little to be desired in consistency. This new process is on the nut dimensionally and rates 1400 on the Knoop scale.

Don't ya just love technology.Keep us posted.

carbon,
<br>
<br>I have not been privvy to oodles of chrome-lined bores. Mostly on Bushy AR's and I simply LOVE them. That due to abuses they will happily suffer,zero maintenance and errosion is minute. Then the damned things shoot scary sized groups to boot. Chrome lining doesn't "scare" me.
<br>
<br>I nearly bought an FN SPR,just to dicker with a chrome-lined 308Win bolt gun. The chrome idea very much appeals to me,though I realize that current technology doesn't allow the process to hang with best grade Custom tubes(uniformity,interior finish,etc.).
<br>
<br>As you learn more about the process you mention,I'd love to hear any inklings you'd care to reveal. It's GOTTA be the future of barrel making technology.....................

Stick,
<br>The 240 Gibbs is done and ready to go to be Ultracem plated. This process is a nickel-boride coating that has lubricity, high hardness and erosion resistance, facilitates heat transfer and looks pretty too. All the properties that make it a great bore coating make it a great overall finish to boot. The basic process turns out looking like a French Grey finish. The folks with the Ultracem process can evidently manipulate the process to different colors. If that is perfected, I'm going to turn the Gibbs into the ultimate pimp rifle. Bright blue action, black carbon barrel with blue accents on the breech stainless and muzzle nut, all set into an electric blue laminated stock. Or maybe not, we'll see.
<br>
<br>Here's a link to more info on the Ultracem process - http://www.universalchemical.com/products/ultracem/index.asp

Is it possible that you could PM me some ballpark figures on the barrel treatment? Or if you prefer another means of communication,let me know.
<br>
<br>I am most curious and interested....................

Stick,
<br>When we take this product to market, I believe it will be on barrels with bores cut a little oversize to accomodate the plating. Thus the price will be cost of a barrel plus the plating. The 5R cut rifled barrels plus plating will be a little more than a select match from Shilen. Retail pricing is not yet established, I'll check with the other principals and advise. PM your phone number and a good time to call. We can visit about this on my dime.

I'm in no greedy rush,but the whole process sounds very promising to me. I was curious as to what relationship bore diameter would play,with the plating process.
<br>
<br>I'll shoot you a PM,it is my bedtime. Appreciate the heads up on the new technology...............
<br>
<br>

Ken. I take it my error was in the belief that heat disapates more slowly through air than it does in metal ?
<br> My understanding was that a heavy barrel absorbs more heat from the get go. Which means more rounds fired before it gets "too hot". Then it would take longer to disapates into air which, I thought/seem to remember doesn't allow the heat to disappate, or spread as rapidly as metal. In otherwords, I assumed it would migrate away from the key throat area and allow more rounds fired.
<br> I take it this may be, but it is off set by the longer cooling time ? E

Carbonman are you just going to leave us all hanging wondering when this new barrel will be out.

Sorry to leave you hanging. The board met last night and more info and a fall special introduction will be announced in less than a week.

Carbonman any new info on the barrels?

Stick,
Here's an image of the external plating using the Ultracem. Greasy fingerprints notwithstanding, you can see how the plating follows every detail of this relatively rough lower.
Barrel bore coating is going to be announced at the SHOT show next month and will be a go to sell at that point.

I've been mentioning the process to pards and there certainly is unanimous interest. As details unfold,please keep sharing them.

I appreciate the update.................

I noticed the AR lower has a broken guard boss, another one of those basement gunsmith screwups?

Dan

Dan,
If there is something busted on this lower, you'll have to point it out. I'm not seeing it and I have it in my hands.

The trigger guard assembly is held in place with 2 pins, the front captive pin and a rear roll pin, the receiver is missing one side of the receiver boss that the rear pin passes through. It is easy to see from the photo. I have seen more than one of these bosses broken by someone using a hammer to install the pin in an unsupported receiver

Dan

DFC,
You are the victim of an optical delusion. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" /> The scanner I use for quick images got you. Here's the bottom view.

I'm very sorry at this point, that I posted my original statement about the broken boss. I'm not buying your statement about it being an "optical delusion" As I believe it's optical elusion. I don't make mistakes in examining a picture, either your camera is not of high quality or your scanner is defective. If, in fact the lower is not broken, you could always post a picture showing the serial number and both guard bosses. Don't do it for me, I'm not interested at this point.

Dan

DFC why all the hostility? <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />I don't think that it really makes any differance if the boss is broken or not.I think that Carbonman was trying to show use what his plating looked like.Maybe I am sticking my big nose some where that is does not belong.If so I am sorry.

Dan,
I don't take kindly to folks questioning my integrity. This lower is not for sale and I have no reason to hide a broken part. I'm unsure of what your motivations are, however, in this case you did make a mistake in examining the picture.
If you are not interested you sure have wasted your time and mine on this sidetrack to the thread.

I don't take kindly to folks questioning my integrity."
I feel the same way about my intelligence, I hate it when someone insults it. Why are the color hue's different?

Dan

Your email claiming I'm inserting an old image is ludicrous. The light and contrast do differ on the images,
secondary to adjusting for the dark first pass off the scanner. That's why anyone seriously interested in the process gets a sample coupon of stainless or CM to look at it first hand.

I don't know why you insist on grinding this axe. As far as your intelligence is concerned, I didn't intend to insult it but I do suggest spell check.

I agree, the point is trivial. Trouble is you made a mistake (understandable with the poor image quality I posted) and now you aren't big enough to back down.

Let's get back to the topic and leave this.

Tell you what, you bring that receiver to the shot show, I'll be there and will look at it, if I can't find where you glued the piece back on, I'll buy you and your wife a steak. And you can eat it when you get home.
PS: I have speak and type and now and then it screws up, most of the time I check it, but this time I don't check it for accuracy.


Dan

Sorry about getting off the topic at hand. I don't have any opinion on whether they fry any faster than a standard barrel. However I have in the past sectioned several dozen take off barrels, just to see what they look like around and in front of the chamber. One thing I have noticed is massive cracking for the first 12" or so of the barrel, the length of the cracking was dependent on the caliber and number of rounds shot. The point here is the cracks may come from expanding metal when the high pressure is pushing the bullet down the tube. like a duck egg in a Rattle Snake. Now we turn the barrel down to a skinny tube and coat it with whatever is popular today. I wonder what that egg in the snake looks like?

Dan

DFC
Why don't you send him that chip off your shoulder for plating, the way you are tossing it around you might just wear it out!

I would bet he would take the steak home rather than break bread with a personality like your's...
art

sitka deer,
"DFC
Why don't you send him that chip off your shoulder for plating, the way you are tossing it around you might just wear it out!"

Having read your negative post several times looking for the hidden meaning, you must have disguised it rather well, I give up. Would you like to tell me what your post has to do with the subject at hand. other than your personal opinion about my personality, which by the way is mine and may not be perfect, but then I didn't stick my nose in your business, did I?

"I would bet he would take the steak home rather than break bread with a personality like your's" I sure as hell didn't invite anyone to dinner. You are quite funny art.

Dan

Carbonman don't sweat DFC, he just likes to spread his love where ever he goes. Oh and btw DFC that SUCKS action you wanted me to virtually give away turned into a Sako 579 (older model). Had I listened to you the only thing I would of got out of the deal was screwed.

Gentlemen,
I haven't written DFC off, nor am I bearing a grudge. I'm pretty certain that he and I have met before and we got along great. I can't place the face with the name or a place but I have a hunch. I may be missing something but I have the impression he has made many positive contributions to the forum. Sadly this thread has fallen victim to less than productive posts.

I'll have the lower in Orlando with me and many folks will have a chance to look at it. DFC may or may not introduce himself when he inspects it.

I used to be able to post the URL of this link as an informational thread. That's pretty much fried now.

Mike
I apologize for any part I played in debasing the thread... will gladly delete my post if you like. I only thought it absurd that someone would be so openly hostile over his own misjudgement.
art

Mike, I know I'm part of the distraction from the subject at hand. Out of respect for you I'll leave the rest of this thread alone. Doesn't change what I think of one certain poster, but I think he knows that by now.

Carbonman, not that I think you need the help, but I'll delete all my posts. And old BIG SKY can ( you guessed it)

Dan

I'm real sorry about what happened here. I'm not able to delete them.

Dan

Well, what I want to know is, did DFC inspect the lower unit in question at the SHOT show and buy you a steak, or did he not introduce himself and sneak off into the sunset as I suspect happened?

If we thought it was any of your business, we would have posted it.

Dan

Pardon your flatulence.

IIFID
The funny part is that I bet you thought you were going to get an adult answer. Clearly a loser...
art

You're right he is "Clearly a loser..." Good thing you used the word thought rather than assume, huh.

Dan