Birch is supposedly 25% stronger than walnut. If you plan to use and/or abuse your 10/22 go Birch. If your 10/22 is mostly going to be displayed/admired, go walnut.Ruger uses birch from Maine for their stocks. On a scale of 1-5 both birch and walnut have a hardness rating of 4. Walnut is more desirable for gun stocks because it usually has more and darker figuring in its grain. While the visible grain in birch is lighter in color it looks better if it is stained to more closely resemble walnut and when scratched a lighter color is revealed. If you are concerned about scratches and the lack of figuring in birch then find a walnut stock if you can. If you want something just a durable but at a lesser cost then birch should be your choice.