Quote Originally Posted by ger21 View Post
That claims .015% per 1% of moisture content change for baltic birch (finnish birch).
MDF is .05%, which means it shrinks and grows 3x more than baltic birch.

Any wood construction should be sealed as well as possible, which will greatly reduce movement.
i use a sealant on wood but the issues for me usually arise from the moisture that is already in there. The walnut stock blanks I buy can be considered dry enough to use when moisture gets down to 6%. I have never seen any with 0%.

It's not really an issue on a deer rifle. It's a big deal for me though because I use the stocks as master plugs when making rigid molds (for carbon fiber). If the wood expands, even a little, it either gets stuck in the mold or the mold cracks. Or, I have indexing issues when I make the second mold half.

I have gotten around thus issue by making resin castings in silicone before making the rigid molds. Now that my cnc machine is up and running though, it would be nice to be able to use wood directly. I am going to order some Baltic Birch this week to try.