Why use a carbon wrapped barel?

[Pdvdh]

I disagree that it wont be put to rest. Someone with good knowledge of these formulas could post numbers and clear this all up. If no one else does, I'll figure it out and post.

You haven't posted anything to clear this all up. Are you working on figuring this out? To clear this all up and put it to rest?

 

[JAYgs8163]

A barrel that is .550 at the muzzle is like a pencil profiled barrel. The CF barrel with a 9 twist was probably not stabilizing the bullet or it was so velocity fast it was causing issues to the jacket at 3400 FPS.

 

[Mram10us]

You haven't posted anything to clear this all up. Are you working on figuring this out? To clear this all up and put it to rest?

Priorities right now are not this topic

 

[atblis]

Liner at the muzzle on CF has to step up, so some extra steel there for the CF wrapped barrel. Not much...

 

[atblis]

Are we assuming isotropic thermal conductivity for the CF?

 

[Rich Coyle]

If I read his post correctly he had a much bigger diameter on his carbon barrel. So it makes sense to me that they could have weighed he same. So he was comparing apples to oranges.

I was comparing one barrel I owned with another barrel I owned. I was curious so I weighed them. It should have been included the steel barrel went to Twisted Barrel where they put heavy flutes in it and took off seven ounces.

 

[Rich Coyle]

A barrel that is .550 at the muzzle is like a pencil profiled barrel. The CF barrel with a 9 twist was probably not stabilizing the bullet or it was so velocity fast it was causing issues to the jacket at 3400 FPS.

The 3,400 barrel shot very well. But it was a Lilja stainless barrel on a Savage action. The carbon barrel was on a Pierce and never shot well. That's why I disassembled it and sold the parts: Even down to the Trigger-tech trigger. When the gunsmith put together my two rifles I had him do the Savage for my son-in-law.

 

[Pdvdh]

Are we assuming isotropic thermal conductivity for the CF?

Until there's a good reason to not do so.
You realize that if the thermal conductivity is improved longitudinally, that the heat will have to travel a very long distance to reach the end of the carbon fibers in the carbon fiber wrapped barrels I've seen.
And that all the carbon fibers are embedded in epoxy resin.
Both of these factors act negatively towards the argument that heat flows exceptionally well longitudinally down the length of the carbon fiber strands.

 

[Calamity]

Have any of you folks with the means ($) to do so, ever
investigated having a barrel made of a super alloy like Inconel 625? The rifling could be created using an EDM process (Electric Discharge Machining). If "barrel burners" like the 28 Nosler were made this way, they might be more immune to wear and throat erosion, even using extreme pressure loads. Here is a source if anyone wants to pursue the idea: https://www.applegateedm.com/
I have used them in my business, and can attest they do fine work. I do not know if they have ever made a barrel, but they certainly have the capability.

 

[Rich Coyle]

Until there's a good reason to not do so.
You realize that if the thermal conductivity is improved longitudinally, that the heat will have to travel a very long distance to reach the end of the carbon fibers in the carbon fiber wrapped barrels I've seen.
And that all the carbon fibers are embedded in epoxy resin.
Both of these factors act negatively towards the argument that heat flows exceptionally well longitudinally down the length of the carbon fiber strands.

Well then, can we surmise the chamber end heat will then be transferred to the muzzle end quicker than normal; thus ever so slightly helping the throat to last longer?

 

[Pdvdh]

Well then, can we surmise the chamber end heat will then be transferred to the muzzle end quicker than normal; thus ever so slightly helping the throat to last longer?

You could surmise anything you prefer, but I can't imagine why one would surmise what you've suggested.

The distance heat must travel to be transferred is just as big of an impediment to efficient heat transfer as a lower thermal conductivity coefficient. Travelling down the spiraling carbon fiber length over the 18-24 inches of straight barrel length, is a long distance for efficient heat transfer, compared to transverse heat transfer from the bore radially to the surface of the carbon fiber.

The shortest distance between two points is a straight line. Carbon fiber wrapped barrel fibers I own aren't wrapped in a straight line. Spiral wrapped from the chamber to the muzzle. This greatly increases the heat transfer distance down the length of the fibers. So for those who contend the heat transfers very efficiently down the length of the fibers? Well it better transfer more than 100 times more efficiently, because that's how much greater that distance is than the distance from the bore surface to the exterior adjacent surface.

The improved thermal conductivity coefficient for carbon fiber that would be most helpful is in the radial direction, where the heat only travels less than 1/2" from the surface of the steel bore to the surface of the outer carbon fiber wrap. I've never heard of improved carbon fiber conductivity coefficient transverse to the carbon fibers.

Worse yet, all the carbon fiber is embedded in epoxy. The heat also has to travel thru that epoxy, which has a worse thermal conductivity than plain barrel steel.

If anyone's pet carbon fiber barrel transfers heat better than all steel barrels, I'm happy for the associated peace of mind.

 

[Rich Coyle]

My ignorance was hoping.