Yes, we should all be buying it to support their expert work.
Carbon fiber barrel longevity?
- Thread starter Bigeclipse
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yes i am being paid to sell their books, LOL- Expert or not or whatever you want to call them they put the time in and you did not. I doubt you've spent your own $$$ on 10+ different barrels and thousands of reloads and or thermal equipment. and im sure you did your own extensive research. I'm not selling anything nor could i care less if you buy the book or not. Im just giving my own opinion about a $35 book that costs nothing in the grand scheme of equipment in long range shooting. And again if you like to read its a good book of information!
Heat always transfers from hot to cold through a process physicists call entropy. The heat originates from the hot bore and transfers to the cooler external surface of a steel barrel.
Steel (and other metals) conduct heat through the free electrons present in the iron atoms. As the steel heats up these electrons increasingly vibrate and collide with nearby electrons. These nearby electrons increase their vibrations which excite more electrons and so on.
A material's ability to conduct heat can be measured, steel is around 50 watts per metre-kelvin. High carbon content carbon fiber, from one end of the fiber to the other, is 500W/mK. Wow! That's great! Tens times more heat conduction than steel. But alas, there's more to this.
Looking at the one manufacturers CF barrels, they are laid up with the fiber running from muzzle to breach and back again but that is not the path the heat takes. In order to take advantage of the superior performance of CF you would have to lay up the CF with the fibers running from the steel bore core to the surface.
So what is the thermal coefficient going across the weave and resin of a CF barrel? I found data that says it's anywhere from less than 1W/mK to 5W/mk. The latter is for a resin that has metal powder mixed in it to improve thermal performance. So, CF across the weave is not a very good conductor of heat and that is why the CF barrel stays hot.
Would I use a CF barrel in a hunting rifle? Yes, if it produces the accuracy I want. Would i use one in a high capacity auto loader? Probably not a good idea.
Steel (and other metals) conduct heat through the free electrons present in the iron atoms. As the steel heats up these electrons increasingly vibrate and collide with nearby electrons. These nearby electrons increase their vibrations which excite more electrons and so on.
A material's ability to conduct heat can be measured, steel is around 50 watts per metre-kelvin. High carbon content carbon fiber, from one end of the fiber to the other, is 500W/mK. Wow! That's great! Tens times more heat conduction than steel. But alas, there's more to this.
Looking at the one manufacturers CF barrels, they are laid up with the fiber running from muzzle to breach and back again but that is not the path the heat takes. In order to take advantage of the superior performance of CF you would have to lay up the CF with the fibers running from the steel bore core to the surface.
So what is the thermal coefficient going across the weave and resin of a CF barrel? I found data that says it's anywhere from less than 1W/mK to 5W/mk. The latter is for a resin that has metal powder mixed in it to improve thermal performance. So, CF across the weave is not a very good conductor of heat and that is why the CF barrel stays hot.
Would I use a CF barrel in a hunting rifle? Yes, if it produces the accuracy I want. Would i use one in a high capacity auto loader? Probably not a good idea.
Wedgy
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- Feb 9, 2013
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So the CF in this case is more of an insulator, trapping the heat in the steel barrel ?
It has to be, or the surface would feel hot like a steel barrel. The powder did explode, and produce the same heat in a CF barrel as in a steel one. Therefore, I suspect it is NOT wise to put a lot of rounds through a CF barrel without cooling time between shots.
Yes, CF acts like an insulator compared to steel. It does trap heat in the barrel as it doesn't allow it to dissipate into the atmosphere as efficiently as steel does. Styrofoam has around 0.03W/mK thermal coefficient. I'd call styrofoam an insulator.
A CF barrel has less Thermal Mass than an all steel barrel and this causes it to have less Specific Heat Capacity than the steel barrel. As a result of that and the fact the heat cannot escape as quickly, the temperature of the CF bore core will rise higher and faster than the bore of an all steel barrel given the same loading and tempo of fire.
Some people on this website have suggested having a fan blow on the barrel to help cool it. I think it would be more effective to blow cooling air through the bore. Water would be a much more efficient bore coolant but I'd be very hesitant to use it as it could cause thermal shock to the barrel and damage it. Depending on how hot the barrel is you might even get scalded by the steam.
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T
Water would be TERRIBLE. Not only would it cause thermal shock; it also would hasten oxidation of the metal barrel lining (translate that: rust, corrosion).
cjl2010
Well-Known Member
Had a Christensen arms barrel for about 10 years. Looked good as new.
Cliff: I also have a CA rifle, with only a couple hundred rounds thru it. What special measures did you take to care for it?
cjl2010
Well-Known Member
Not a thing. My sister and her husband backed over it and pulled forward over it again and that took the smallest little chunk out of it and that never grew or got any worse. I did not do anything special other than wipe the blood off of it at the end of the year.
Wedgy
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This may come as a surprise but there are many guys, even well decorated BR shooters that cool their barrels with water while out prairie dog shooting. I have never done it but I have seen it work, push a patch thru then back to shooting, very accurately. The inside barrel surface is only really hot for a flash then it is absorbed to the rest of the barrel so it isn't glowing when you dump the water in it. Not hot by metallurgy standards anyway, I think you would have to have it glowing hot then quench it to have ill effects or else they wouldn't be doing it.
There are other types of carbon barrels with air space around the steel so it can cool, compression and tensioned barrels, They address insulation at ~4:30 in this video, interesting series.
https://www.longrangehunting.com/threads/jp-enterprises-3-port-brake-5-8-24tpi-308.222873/
But back the the OP's question of wearing out/delaminating.... I don't think it is an issue or someone would be posting pictures. Call Proof and ask what their warranty is.
lancetkenyon
Well-Known Member
I like and trust them enough that I just received my 5th Proof barrel for a new build.
6Creed 24" 1:7.5" Sendero
6.5SLR 22" 1:8" Sendero Light
6.5SS 26" 1:7.5" Sendero Light
280AI 26" 1:9" Sendero Light
And the new one will be:
25SST 26" 1:7.5" Sendero
6Creed 24" 1:7.5" Sendero
6.5SLR 22" 1:8" Sendero Light
6.5SS 26" 1:7.5" Sendero Light
280AI 26" 1:9" Sendero Light
And the new one will be:
25SST 26" 1:7.5" Sendero
That is a great idea. Water has a very high heat of vaporization and even a little bit of it will remove a lot of heat when it turns into steam.
