Rustoleum Camo paint in gray for base, some matte black for the lines and green and black for the spots. For the spots you use a natural sponge and rip it apart to give you different patterns. Jusgt spray a puddle on a piece of cardboard and dip the sponge piece in it and dab it on the stock randomly. Next one I do I'm going to add a mud brown color to it.
After its to your liking you protect it with a couple coats of matte finish polyurethane.