I dealt with a cracked pistol grip by drilling through the pistol grip from top down inside inside. I purchased a 12 inch 1/2" drill bit and going through the inside was able to create a 1/2" hole through most of the pistol grip. Since I did not go through from the bottom, you can't see the hole. I filled that hole with a two part epoxy, Evercoat epoxy
http://www.evercoat.com/product-detail/base-part/100642/us/. I think I got the stuff from Home depot or a Marine boating store. The stuff has the consistency of honey and will flow. Just filled the hole and let the epoxy cure. The theory is, the epoxy is stronger than the wood. I have seen Anschutz stocks, with sheared pistol grips, and the repair was a bolt through the pistol grip. But you could see the bolt end.