First let me stress that I do not have the definitive answer on this one. However, I have had Christenson Arms' carbon-fiber wrapped barrels on 2 of my guns. It is not a carbon barrel, rather it is a barrel, turned down on a lathe to small diameter, wrapped in carbon fiber. They use Shillen, stainless match (but not premium-match)if I remember right. Neither one would shoot 1/2 MOA groups so I replaced them. (Plus I needed a faster twist by then for shooting a different bullet). One was on a Tikka action and the other on a Sako 75 action. My rifle-smith who replaced the barrels said it looked like the gunsmiths at CA did not know how to properly true the actions and in the case of the Sako 75 did not even attempt to lap the 3 lugs. When I asked the CA people about the Sako lugs they said because there were 3 it couldn't be done. Wrong. Iy just takes more time and care.
Anyway, I don't feel the barrel (inside where it counts) heats up any more slowly than an unwrapped barrel. This has been one of CA's claims. I don't have any scientific evidence to prove my opinion.
Bottom line is if you want a light-weight rifle to carry and shoot good (in my case 3/4 MOA or so) but not great, go with it. Although, perhaps if you stick with one of the actions they are more familiar with the rifle will achieve their 1/2 MOA stated accuracy goal.
[ 03-03-2002: Message edited by: Len Backus ]