Sitka-
I am confident that you are willing to argue about the definition of a crossbolt as well as the color of the sky for the remainder of 2016, which is fine.
For anyone else interested in a) the problem of a stock cracking through the recoil mortise and b) one proposed solution, this thread does a good job of explaining and visually demonstrating what's going on:
http://forums.accuratereloading.com/eve/forums/a/tpc/f/4711043/m/7211094102?r=1181065102#1181065102
