When Bill Sweetland compressed the cedar bolt it was not a parallel piece. It was tapered being thicker on the point end than the nock end. It was then compressed until it was parallel, thus the point was denser than the nock end. It was then doweled. The difference between "Battle shafts" & "Forgewoods" is the Forgewood was the #1 quality shaft it was extremely straight, Battleshafts were seconds and slightly crooked, these were cheaper in cost. In acutally Bill got the idea for compressing an arrow shaft from his father. His dad during WW1 was trying to develop armor for the military and compressed every variety of wood he could fine. Bill once told me, in his opinion the only specie that could be successfully compressed into an arrow shaft was POC. Its no wonder there have been failures by those that have tried using Bill's equipment with other than POC.
Keep in mind POC's moisture is an oil, that when steamed and compressed becomes a binder that holds everything together. It acts like a natural glue. They were probably the most durable wood arrow I've ever used and one of the reasons when found they command such high prices from people that know just how good they are.
Bob