Brent
I have had to repair quite a few failed repairs that used metal rods. I have not found the need to use them personally. The wood is strong enough and the glues stronger yet. Adding another element with potential expansion and adhesion problems does not make sense to me. Were I to use a pin it would be threaded...
I think the biggest problem with cracked stocks, assuming the grain flow is proper, is when the wood moves, usually shrinking, and affects the way recoil is absorbed. Fixing that question is the answer, IMO.
art
