well here are some thoughts
I used undercoat for trucks on the butt of my M1A but it pealed off after a few months after that I got some role on bed liner for the local auto parts store and some rocks from my wifes fish tank (dont tell). I rolled the stuff on the butt and sprinkled the rocks over the top. Then I used some black Krylon to paint the rocks it worked great for keeping the butt in my shoulder during rapid fire.
Another option would be heat stippling but I would use caution in doing this as I dont know what the B&C stock is made from. I did it on my Glock frame and the old stock that came with my savage but it was plastic.