I used red maple. It is commonly available down south and is more stable than sugar maple which lets you get away with using a cheaper, slab, cut of wood. Most people make completely utilitarian chunk guns and therefore use a piece of plain wood. I would still want the grain curving through the wrist. I have seen walnut, but I think maple is the clearly superior stock wood. The dimensions of the blank would basically be the same as any other large gun.
