If you want wood suitable for a gun stock, you are going to have to go to somebody that cuts the tree with gunstocks in mind. This lets out all the folks that primarily produce lumber for furniture and home construction. Only the bottom six feet of the tree, the stump, are good for gun stocks. Most lumber cutters leave this in the ground. You see, the grain needs to run through the wrist (parallel with the wrist). You can only get this where the grains turns to flow out towards the edges of the stump. The best wood is quarter-sawn (trunk quartered relative to the center) and stump cut. This should be considered a minimum qualification for a top quality gun stock. You then add figure on top of that.
Most stock wood is actually slab cut (all wood slabbed off the trunk in the same direction). You have to evaluate slab cut wood very carefully. I will only buy red (softer) maple that is slab cut because red maple is generally pretty stable. For sugar (hard) maple, I will only buy quarter sawn because it all warps and you want it to warp up and down, not left and right. Red maple also warps; it just tends to not warp as much. You still want to look at how the grain runs through the wrist; no matter how the wood is cut.
There are two things that follow from the cut of the wood; those are the direction of the warping of the forearm, and the sides were the figure are most visible. Quarter-sawn lumber has the growth runs running horizontally through the cross-section of the stock blank. This results in quarter-sawn lumber warping up and down, and in the figure being most visible on the sides of the stock. You see, wood warps perpendicular to the growth rings. The figure, if any, is, likewise, most visible perpendicular to the flow of the growth rings.
With slab cut wood, the growth rings run vertically through the stock. Given that the wood warps perpendicular to the plane of the growth rings , that means that the forearm warps left and right. as it is harder to correct aim for windage as opposed to elevation; you don't want a slab cut stock in a wood that tends to warp more. Walnut is a very stable wood and is not a big problem being used in a slab cut gun stock blank as long as the grains runs through the wrist. Lastly, in a slab cut gun stock with figure, the figure is going to be most visible along the top and bottom.
If you can't see the grain (end grain or otherwise) clearly, you can judge the cut of the wood and how the grain runs through the wrist by looking at where the curl shows the most and whether the curl is perpendicular to the long axis of the stock. Curl should always be perpendicular to the center line of the wrist.
I hope this helps with your wood selection.
