I'm with ya on the spine. I shoot the 300's @ 27 3/4" which, according to all the charts is overspined by a bunch.

I do shoot TT shakey hunter as well and I think it's pretty well tuned. I know the cams are on and bare shafted to bullet, fletched shaft rode straight through as well but when I tune for groups at 40 I wind up with just a little left-high tear through the paper...could this be a symptom of overspine?

Anyway, I guess I'll just strap on the B heads and give it a whirl and see where I hit.