Carbon Fiber Wrapped Barrels

[Black Diamond 408]

James,
He runs the wrapping in lots, it depends when you get your barrel into the shop. He might be running military barrels and or contract jobs. He then will run civilan orders in one group. So i cant really say for sure his lead time. My 416 barrel i had done took about 4 weeks as he was just finishing up a contract and the civilian orders was about to start. I have had it take up to 4 months but that was when he was doing it all by himself, now he has hired several workers and he said that it has speeded up the lead times. Best is to try and contact him and see what is currently going on in his shop. The best way is to have the blank made to his specs and send that to him so he dont have to do any ordering as that all takes extra time on his end. I had Benchmark make my last barrel for the wrapping, it turned out great and light. It is 1.450 breech tapered to 1.200 muzzle 32" The barrel was 6.5# I used a Titainum muzzle cap as Stainless is a standard item. I wanted to keep as much weight down as possible. The real weight reduction is the steel liner, it needs to be as light as possible. There is only about 8 ounces of Carbon wrapped onto the barrel, so that will give you an idea on what the barrel will turn out to be. Once he gets the barrel blank, he still has to do some contouring of the breech end and thread the muzzle for the cap. After the barrel is wrapped (looks like a bunch of thread and goop) it is cured in an oven for an extended time, then it goes to the CNC grinding machine to put on the taper. I had Lawton make me two blanks for the 338cal, Barney sent them to me unlapped and wanted them back after the process was done, both of these are super shooters(5# barrels), dont know if it made a difference or not when the lapping was done. I have had Rock, Lawton and BenchMark, all have been super shooters. I had one Rock that turned out on the heavy side, the liner must of been a bit larger (7.5#). When i was in his shop i picked up a 50BMG barrel and it couldnt of been much more than 8#, was going on some mil spec test rifle.
I havent talked with Mike in a few months so im not sure what his current times are.
It is worth the wait if your building a specialty rifle.

Dave

[Sendero_Man]

Is ABS still in Lincoln ?

[Black Diamond 408]

Yes they are still in Lincoln Ne.

[Colcalcipherol]

Finally there is a topic where I can make a legitimate contribution. I'm a PhD physical chemist with considerable experience and knowledge in thermodynamics. There is some debate over whether the carbon wrapping insulates or helps to cool a barrel. These wrappings are made of a very, very interesting, graphene- or graphite-like material consists of highly ordered carbon atoms. The high degree of ordering enables enhanced thermal conductivity by means of phonon transport which is the vibration of a lattice. Image several pool balls aligned perfectly on a table at short distances (say two inches apart). A person who is a decent shot can put energy into the que ball and transfer it down the line to the last ball which takes off at nearly the same speed as the incident que ball (and in the same line if everything is perfectly aligned). In the carbon fibers, the carbon atoms align in such a way that thermal energy can pass through the material via intermolecular collisions (like the pool balls) due to the extremely high order—which basically means that they are just lined up in the perfect manner. Let me give you some numbers: the thermal conductivity of carbon steel is 36-54 W/m/K while stainless steel is 16.3-24 W/m/K. You’ll notice that it takes stainless a little longer to cool than carbon steel—this is why. These fibers, constructed of carbon nanotubes, have a thermal conductivity of 3180-3500 W/m/K! So, you can see that they are not insulators and that they will conduct heat very, very well.

I am having a .375 CheyTac built and I have asked my smith to use a Proof Research (ABS) carbon wrapped barrel. I’ll report back after I have put her through the paces.