Ok let me see if I can word this w/o sounding like a Idiot. Does anyone know what brand of arrow ie, carbon exp. beaman, easton, etc has the highest spine for it's weight. let's try this? if you are trying to make up arrows with as much FOC weight as possible I think it would make sense to start with a arrow with low mass weight but still enough spine to fly straight with a lot of weight on the front, 300 to 400 grains of broadhead and insert would give you a very high FOC but all is for not if it doesn't fly straight, also if you start with a very heavy arrow and by the time you get it to a high FOC state it might weigh 800 or 900 grains. A little too heavy for most bows. LET ME KNOW WHAT YOU GUY'S THINK. I hope I explained my self suffiencly.