Discovered this interesting bit of wisdom about the kind of wood that is good for a gun stock in Surplus Rifle Forum. It’s cool because it describes some hardwood characteristics AND what is desirable in a gun stock. Some of this knowledge might carry over into my index card docks. I have some Home Depot poplar that I’m using.

Excerpted from user tkb447’s reply:

Theoretically, ANY type of wood could be used for a gun stock. It is not a matter of whether is is possible….but only how suitable is the particular wood in question. Oak is not popular for gun stocks simply because, though it is hard enough….and a strong wood, grain variability is very great…wide vs. narrow growth rings, the thickness of the heart wood, checking and cracking problems as the wood dries, etc. etc. Walnut, Maple, and several others offer much more consistency in this regard….so they are considered more desirable for this purpose. Poplar is a close, straight-grained wood, but somewhat marginal as to it’s hardness (it is considered a hard wood, but just barely….it is also rather plain- looking). So, it has never been considered highly suitable for stockmaking. One of the other posters (Huffmanite), hit on a good compromise. Many woods which may not be suitable as solid pieces (for gun stocks)….may in fact perform much better when used for laminated stocks. Evidently, Poplar fits into this category. Birch is another example….it is very commonly used for laminated stocks….but not very suitable for solid wood stocks. The criteria for suitability of a good gun stock wood are as follows : how close and straight is the grain…..can the wood be dried to a consistent moisture content (and is the wood stable when dried)….is the wood subject to shrinkage/ checking/ curling/ cracking problems when dried or finished – this is largely a function of the grain consistency of the particular species….appearance (does the wood tend to have a nice figure, or is it plain and muddy- looking)….workability/ machining issues….tendency to “end split” or shatter when dropped….how the wood takes a stain and finish….how hard and ding- resistant is the surface….etc. etc. etc. Some woods are simply better than others, within the context of these criteria….it’s as simple as that.