IMO, Feibing's leather dye is a poor product for leather, and even a poorer stain for gun stocks. It sun fades, and is bad to come out blotchy, or streaky, on leather. I much prefer Lincoln's which is much more colorfast, and has a lot more pigment, and not so much carrier, in it.
Auquafortis or similar acid stains, is more labor intensive, but really is the best there is for maple. Once you learn how to control, and manipulate it, you can start getting the most value out of a piece of curly maple.
Hungry Horse