RE: Results from spine-tuned arrows
Your results are amazingly similar to mine. I came to the same conclusion with the stiffer arrows. When you're spinning the arrows on the tester and seeing one at .340 and another at .325 or even .315, it becomes very obvious that in a borderline spine situation, the weaker ones are not going to fly the same way the strong ones will. It makes good sense that they should all be strong.
I've been shooting these for a few days now, and even with broadheads, I am still getting groups that are smaller than what I would normally get with field tips on the same arrows. I did get to shoot on a day with little or no wind and my 60 yards groups were very good (for me).