Once I get my barrel and finish it up, I'll post some photos.
ETA for the barrel is aprilish.
here is the link to the barrel
http://proofresearch.com/barrels/
Some years back, one of the big shotgun manufacturers, Remington or Winchester I can't recall which one, made a shotgun with lined fiberglass barrels. (I don't think carbon fiber existed back then.) They were good guns, and really light, but they never went over very good, so they only made them 2 or 3 years. The new Ruger LCR revolvers have a lined polymer barrel, and they seem to work good.