Just got some MAJOR sticker shock from AD's and Grizzly Stik shafts, they are out of my league as hard as I am on arrows haha! I do like wood, but just starting out I really prefer carbon's as they can easily go from broadhead to fp to SGT with a few twists and I don't have to purchase a burner and fuel etc. I was looking for heavier weight carbons, and found the Carbon Express Pile Driver Hunter arrows are 10.4 gpi with their 250's (.402) spine. So I figure with a 32" arrow, 75 grain insert, 200 grain VPA 2/3 blade head, and feathers I should be right around 615 grains out of a 54# bow that should be good I would think. Anybody care to enlighten me as far as how to figure out the foc if I don't actually have the arrow handy?!?!