Very interesting. Thanks guys! What precipitated all this, was my arrows were over spined with 125 grain tips. The pro shop talked me into cutting them down to 31 inches when I bought them. I was reluctant, but according to the spine chart they used, at my draw weight, full length should be 340 spine. Well, the 400's were too stiff at 31 inches and 125 grain tips.
Ashby's studies intrigued me, but I told myself to stop overthinking things and just do it. However, I got tired of struggling with over spined arrows, so I decided to give it a try. In my backyard, maximum 18 or 19 yards, the heavy arrows, with 350 grains up front, work fine and fly great, right on target (maybe a little stiff if I don't get my back tension right locked out every time, like someone suggested a couple posts up). I had a test kit, so I bare shaft experimented from about 225 grains up front, but the bare shafts flew best when I got up to 350. Yes, my arrows are slower, which is some of my concern, and why I have posted this question. I went to the range last night, and up to 20 yards, my groups are pretty consistently on target and within about a 6-8 inch circle. 30 yards a little wider, but still not bad. 40 yards they were dropping a little early on me, and I really noticed the big arc in trajectory but right-lefts were still pretty good. One of the pros at the range is a real advocate of arrows hitting harder on a downward trajectory. And he liked the arrow recipe for hunting. I found I am way more consistent with the high FOC than I was with the more standard 125 grains up front (which gave me a 470 grain arrow) and 13-14% FOC. Ethically, I would never take a shot at a deer more than 20 yards away, so I think I will go with this. However, I would still like to try a 500 or 600 spine arrow with the same FOC, but lighter weight, for longer shots I might encounter at fun 3D shoots. But that will have to wait until I can afford another set of arrows.