One of the fellows shooting with us down here has a gorgeous set of shaders on his target rifle that look for all the world like well-aged hammered copper. Just gorgeous.
For anyone wanting HC shaders....please stop reading now.
I make shaders out of Sch 20 PVC pipe. Mark 2 lines on a piece of PVC almost as wide as your barrel is across the flats then use a cutoff wheel on a Dremel to cut out the piece between the lines leaving a slit in the pipe that requires the piece to be slightly spread when you put it on the barrel so that the tension on it is sufficient to grip the barrel. I cover the cut edges with a piece of friction tape, and when I get the "slit size just right...they hold just fine. Spray paint the outside with some neutral color...I use brown, then flat black inside. 
After removing the underrib from my Green Mountain barrel...I cut a "Cant Block" out of a piece of 2x2 pine. Rough cut the half-hexagonal shape with a jeweler's saw then final fitting with a small rasp. 
Hope this helps.