Unless you are repairing gaps, or breaks, there is no real need to bed a blackpowder rifle. Being blackpowder guns, they don't experience the pressures, and recoil forces of modern suppository guns. I consider it a waste of time and effort in trying to match up epoxy color to real wood, which you will never be able to do without it showing. The greatest weak area is the wrist, and unless you are going to use your rifle like a baseball bat, even that is pretty strong. Just my two pence worth.
Bill
I started with nothing, and still have most of it left!