Proof Carbon VS Steel deflection test.

[Tulsa Reiner]

I just looked at a couple of OCW tests on another site where the Proof barrel was used. Neither moved around nearly as much as a steel barrel of the same weight. Maybe even less than one of the same profile.

"Neither moved as much as a steel barrel of the SAME weight?" How could the steel barrel weigh the same as a CF barrel, unless it is a much different profile, or longer?

 

[Deleted member 103481]

"Neither moved as much as a steel barrel of the SAME weight?" How could the steel barrel weigh the same as a CF barrel, unless it is a much different profile, or longer?

Carbon barrels are steel barrels contoured to a pencil barrel then wrapped with carbon. A proof sendero weighs about the same as a #3 steel

 

[Triple BB]

Didn't Litz address this issue awhile back in one of his Applied Ballistics books.

 

[User4302021]

"Neither moved as much as a steel barrel of the SAME weight?" How could the steel barrel weigh the same as a CF barrel, unless it is a much different profile, or longer?

Maybe you should reread the post you quoted and think about it some more.

 

[cjuve]

I have multiple rifles that sport proof barrels and if I have my way the majority will eventually. I could care less about the heat dissipation claim, proof barrels really change the way a gun feels and handles, the change in balance is noticeable. You can put together a semi lightweight rifle and not worry about the accuracy issues that come with light weight all steel barrels.

 

[Gord0]

I have very little practical experience with Carbon barrels. I do have a fair bit in other applications. I have looked at them numerous times but can't get past the reservations and have always ended up with a steel barrel with varying contours or maybe fluting to save weight.

That said, Carbon Fiber itself is as good or likely better heat transfer than Stainless - that's fibers only. However when laid up in an epoxy it's much worse. When I've spoken with manufacturers they are quick to quote the bare carbon properties but skip over the assembly. It would be possible to get better with a more complex laminate including copper or silver, etc. but to my knowledge none of the barrels have that. BTW, SS is worse heat transfer (better insulator) than non-stainless by a bit. That's talking generalities and specific materials, alloys and techniques will vary.

LB for LB Carbon Fiber has the potential to be much stiffer than steel. Whether that translates over in the real world I'm still sceptical. And add in the thermal properties and different materials moving against each other we'll see...

Thanks for posting up the test results, it's great information.

I was going to make a big long write-up, but jpndave did it for me! I don't care who's carbon wrap barrel you are using they don't transfer heat as well as plain steel because of the epoxy matrix. Even if you were to use the fancy silver heatsink epoxy that costs THOUSANDS an ounce! You won't get heat related poi shifts with carbon barrels because the carbon wrap doesn't heat up as much as steel because it can't transfer heat as well, and it is thermally stable.

 

[Rhovee]

I think the carbon cools down quicker than steel does. But the pencil barrel underneath there heats up a lot faster than a larger steel barrel. Just going off the warmth of the carbon being warm will torch a barrel faster than you want.

 

[Gord0]

I think the carbon cools down quicker than steel does. But the pencil barrel underneath there heats up a lot faster than a larger steel barrel. Just going off the warmth of the carbon being warm will torch a barrel faster than you want.

You might think that, but it's physically impossible. Carbon fiber transfers heat much better than steel, but it's insulated by the epoxy that binds it all together.

 

[Deleted member 103481]

It's a shame that carbon barrel discussion always deviate into heat transfer. I think the rigidity is something touted just as much.

I found the info presented to be extremely interesting, and did not expect a proof sendero to flex to the extent it did compared to a relatively skinny steel barrel. I was only interested in the manufacturer as I know some will only use chromoly for a #3 and wondered if that barrel was SS or CM. I did notice my last proof sendero had a 3 MOA impact shift down with my 17.4 ounce suppressor mounted, which seemed large to me for such a thick barrel.

 

[Gord0]

It's a shame that carbon barrel discussion always deviate into heat transfer. I think the rigidity is something touted just as much.

I found the info presented to be extremely interesting, and did not expect a proof sendero to flex to the extent it did compared to a relatively skinny steel barrel. I was only interested in the manufacturer as I know some will only use chromoly for a #3 and wondered if that barrel was SS or CM. I did notice my last proof sendero had a 3 MOA impact shift down with my 17.4 ounce suppressor mounted, which seemed large to me for such a thick barrel.

They are touted as being more rigid, along with much better heat transfer. Both, like most marketing, are only partially true. Carbon fiber transfers heat extremely well, but mix it with epoxy and wrap it around a steel tube and it doesn't. Carbon fiber is extremely rigid as compared to steel per weight. Make it thick enough, and it will be more rigid than steel with the correct epoxy mixed with it. Now the up side to a carbon wrapped barrel is they are in general lighter than steel barrels. You also can get less poi change during long strings of fire with a properly tensioned cf barrel.

 

[TX Badger]

There seems to be a lot of conjecture about the heat dissipating properties of cf vs steel, but no real data. Couldn't someone who has both in the same cartridge just shoot a couple rounds quickly then put a probe thermometer a few inches down the barrel from the chamber and note the temp. and how quickly it falls over 10 minutes? Seems like an easy test. I don't have any cf barrels though.

 

[Rhovee]

Maybe I'll do it this winter when I am bored. I have a 7 saum with both carbon and stainless barrel. But you would have the people who would argue, barrel length isn't the same. Load isn't the same. Etc.

 

[Tulsa Reiner]

Maybe I'll do it this winter when I am bored. I have a 7 saum with both carbon and stainless barrel. But you would have the people who would argue, barrel length isn't the same. Load isn't the same. Etc.

I think you would want to at least use the same powder and charge in both barrels in order to generate the same amount of heat in both. Then measure at the chamber end. Barrel length would seem to have little effect, esp if you covered the end of the barrel after firing, and forced the heat to dissipate through the barrel wall only.

 

[Rhovee]

Only issue is the steel barrel can take more powder than the carbon. Not much. .5 grains. But I could just drop it down a grain and let (4) rip with same time between shots. I would put money on the steel one being cooler. I have a Fluke temp gun I can shoot down there. Or get a Fluke temp probe for my digital meter.