Thread: carbon wrapped barrels

So whats peoples thoughts on these, what is the main advantage, if there is any?

Seem a lot of coin for bugger all gain.

They are designed to lighten your wallet.

Read this article, not all carbon fibre is the same

Carbon Fiber Properties-Heat Conductivity

Originally Posted by 7mmsaum

They are designed to lighten your wallet.

Ratio of rifle weight saving: wallet weight doesn't seem worth it to me!

Originally Posted by stug

Read this article, not all carbon fibre is the same

Carbon Fiber Properties-Heat Conductivity

The articles doesn't really say this. All it really says is that the thermal properties differ dependent on the direction you look at it (in plane (perpendicular to fibre) or transverse (in parallel with the fibres))

But, TL;DR: from the article "Conventional carbon fibre and epoxy layups are poor heat conductors"

As far as I can tell, with laying up carbon fibre on the barrel, the thermal properties are going to depend on the ratio fibres to epoxy, which is dependent on the method of layup. EDIT: Also, because you couldn't (in any cost effective manner) layup carbon fibre on a barrel in plane, all barrels will have carbon fibres layed in the transverse direction - therefore comparing a steel (iron) barrel with a thermal conductivity of 80W/m*K, to a carbon fibre barrel with a thermal conductivity of 8W/m*K - a carbon fibre barrel of equal diameter to a conventional steel barrel is 10 times worse at conducting heat away from the rifling.

Did you read the end of be article?

"As usual the answer is "it depends." The short answer is NO not when regular carbon fiber is made up in regular epoxy and expected to conduct heat across the thickness. IF a highly carbonized pan fiber with graphite or diamond added, is measured for heat transmission in the length of the fiber it is very good and can rival and exceed copper.

Other carbon materials such as diamond or some graphites, such as pyrolytic graphite, are stellar and can be 5 times better than copper.

Graphene sheets and Carbon Nanotubes have very amazing potential but are not yet in common use. To be continued..."

I am super temped to try one out

is measured for heat transmission in the length of the fiber it is very good and can rival and exceed copper.

Please explain how to manufacture (economically) a rifle barrel with carbon fibres running in the radial direction to provide a substantial improvement in thermal conductivity over conventional materials?
For all intents and purposes, the only layup direction which is of interest to us is transverse, because the only way to layup carbon on a barrel is with fibres in the circumferential direction.

They are designed to lighten your wallet.

There's a sucker born every minute.

I copied this from another website. Thought it was worth reading. Kirby Allen knows a thing or two about custom rifles.


"I have fitted alot of carbon fiber barrels to custom rifles and have learned a few FACTS from my actual hands on testing. This is what I know:

If you take two barrels, for example, two #4 contour barrels, one carbon wrapped, one all steel, the all steel barrel will be dramatically stiffer. Also, the weight reduction on the wrapped barrel will not be much at all.

If you take two barrels, for example, 1.200" straight cylinder barrels,one carbon wrapped, one all steel, the all steel barrel will STILL be stiffer then the carbon wrapped barrel but in the comparision between these two large diameter barrels, the carbon wrapped barrel WILL BE much lighter in this application.

I know this because have taken barrels, chucked them up in the lathe by the shank just as they would be supported by the receiver, then hung 10 lb weights off the muzzle end and measured the flex in the barrels for comparision. In every case, all steel barrels had less flex then the carbon wrapped barrels.

Its true that carbon is stiffer then steel for a given WEIGHT. That is what gets left out of the advertisments. Let me explain further. If you take two rods that are 30" in lenght, both weighing 5 lbs. One all steel, the other all carbon fiber. The carbon fiber rod will be several TIMES larger in diameter then the all steel barrel and yes it will be slightly stiffer as well. Unfortunately, its not practical to wrap that amount of carbon fiber around a barrel sleeve. As such, the strength increase advertisment is simply FALSE in a rifle barrel application.

Now onto barrel weight.

AS mentioned, if your comparing two rifles with large contour barrels, the carbon fiber barrels will be DRAMATICALLY lighter but their barrels will not be stiffer.*

IF your comparing sporterweight barrel contours, You can build an all steel barreled rifle that is only marginally heavier then any carbon fiber barreled rifle so application is critical to get the advantage out of these barrels.

Now lets talk about barrel life.

Yes its been proven that carbon fiber barrels cool faster then all steel barrels. It has also been proven that the barrel sleeves used in carbon fiber barrels also heat up faster!!!! So its a bit of give and take here. I would say for a high volumne varmint rifle you could see some benefit in barrel life but in my testing, even with large capacity, hyper performance long range rifles, the barrel life advantage is less then 15%.

Considering that a good quality carbon fiber barrel will cost easily twice what an all steel barrel will cost, in my opinion, its not worth it, especially for a big game rifle that will be fired much more deliberately with low volume shooting.

I have tested a couple ABS carbon wrapped barrels in my 338 Allen Magnum and put them through some torture tests along with two all steel barrels, one from Lilja and one from Krieger. The ABS barrels both used Rock barrel sleeves. The test was to fire five, 10 shot strings. Shooting was done by shooting 10 shots as fast as possible. Let the barrel cool to the point I could just hold my hand on the barrel, repeat with 10 more rapid fire shots and continue to repeat until 50 rounds were down the barrel.

I did this with all four barrels, two ABS, one Lilja, one Krieger. After the test all barrels were pulled, cleaned and inspected for throat erosion and heat cracking. In the end, The ABS barrels had roughly 8 thou less throat erosion(throat length) then the Lilja barrels but they were identical, within +/- 1 thou of the Krieger. Heat cracking appeared to be nearly identical in all barrels.

From this torture test it was clear that if you mistreated ANY barrel with a chambering like this, you would not be saved by a very high dollar barrel which is advertised to offer dramatically longer barrel accuracy life. Just not the trueth.

I have also tested a couple rifles shooting them as they should be, this time both were in 7mm Allen Magnum. One was a Lilja 1-9 4 groove, #8 contour, 30" fluted barrel, the other an ABS 30" 1-8.7, 5 groove, similiar contour to a #8 with Rock sleeve.

Both rifles were shot and cleaned regularly, never more then three shot strings. Noticable accuracy drop off started at around 850 rounds with the Lilja, around 925 rounds with the ABS so yes, the ABS offers longer accuracy life but this is I am sure simply due to the different hardness of steel used in the cut rifled barrel compared to the much softer steel used in the button pulled Lilja.*

Still, 75 more rounds for over twice the cost of the barrel was not worth it in my opinion.

I believe the ABS barrels are the very best barrels out there for a carbon wrapped barrel. They do shoot very well, in some applications they do offer significant rifle weight reduction but if used in the wrong application, they really do not offer much over an all steel barrel.

Just my findings."*
__________________
Kirby Allen

Originally Posted by Daggers_187

Please explain how to manufacture (economically) a rifle barrel with carbon fibres running in the radial direction to provide a substantial improvement in thermal conductivity over conventional materials?
For all intents and purposes, the only layup direction which is of interest to us is transverse, because the only way to layup carbon on a barrel is with fibres in the circumferential direction.



There's a sucker born every minute.

I agree with everything you say.

Originally Posted by 7mmsaum

They are designed to lighten your wallet.

Mine certainly did in 2006

I have read the piece from Kerby plus many comments on people who have used them on lite weight builds and a lot went back to fluted steel unless your running 338 or larger where the weight saving can be a lot.

I was very strongly considering grabbing hardy for 338 build before I brought my edge.

Sent from my SM-G935F using Tapatalk

I'm happy with my Proof Research ones so far.....

http://www.nzhuntingandshooting.co.n...minator-25380/

http://www.nzhuntingandshooting.co.n...-magnum-21359/

My 6.5 saum imp is also going extremely well

They certainly aren't cheap & they aren't to everyone's tastes, but they are light, the longer the lighter, compared to steel.

I think the point detracters are missing is for a sporter weight barrel, not sporter dia barrel, carbon is stiffer as the dia is greater. Plus they look cool

Originally Posted by 7mmsaum

They are designed to lighten your wallet.

Classic. Common sense.