Did you read on down on Tapley's site about what is needed to penetrate a solid? He used shields in his example, but says it's momenentum that is needed to penetrate a solid and that an arrow that is too light will bounce off.
That's exactly what I've been saying. It is momentum that determines whether or not a projectile penetrates or bounces off. If it does penetrate, however, it is KE that defines how far.
Earlier, I mentioned using a heavier arrow for extra momentum just in case of a bad shot and needing the arrow to penetrate bone. Same concept.
I agree with this statement. No argument there. Heavier is better for penetration. I've said that all along. Heavier results in more momentum and more KE. But also it is interesting to point out that faster is more accurate, not only because of flatter trajectory but because there is a shorter dwell time while the arrow is attached to the string during acceleration. Same concept of longer brace being more forgiving. But that for sure is another thread.
I think we agree alot more than we disagree.