I think the culprit may have been a fracture obtained from poor arrow flight during the bareshaft testing, and was not detected because I didn't examine the shaft. I've been pretty picky about flexing with carbons, but I admit, I haven't with the wood. The grain appears pretty darn straight. Rifts pointing toward the tip were positioned on top as well, but the arrow pretty much broke in 3-4 places.
Killdeer, I thought they may be a little stiff too. Hildebrand has been right on with his suggestion of 10# over the draw weight (+5 for reflex/deflex, +5 for fast flight). My shafts for my 43# longbow are cut at 28.5, spined at 50-55#, and 125 gr. tips.
This sounds like a fluke, or just some carelessness for not checking them...thats something I can fix. I'm glad this isn't a common occurrence, and i get get some confidence mustered up. It sure does hurt to get stuck....something I won't soon forget. I guess I just have to get back on the horse soon as the hand heals.
Thanks,
Bob