Don -
One thing I have noticed on that soft pine box for my Nambu that I made, is that after milling/routering out the slots, the box halves will warp. The board I selected was nice & flat and stored inside here for a week or so until I milled it. My board and box was stored in my house, in a controlled climate area. I'm theorizing that the loss of some wood, from one side of the board only [the slots], caused an unbalance that allowed the boards to warp.
It took several weeks, maybe months, to warp. I didn't check it closely and only noticed it when I was getting ready to put my 'artillery Nambu' on GB.
