ozy clint; I have some 2317s with 500 up front. Using a 200 grain broad head and 300 grains of 5/16 all thread behind the insert. They weight at 995 grains and are at about 23% FOC and fly pretty well off my 70# No.three bear take down limbs. I get them back to at least 29 inches. They could stand to be shortened up a little but still recover very fast. They are still full length and could be shortened several inches. One of them won't hold a knock, it was slapped on the ground. It comes out when the bow is thrusting the arrow and makes a real strange sound. I don't think I will use them for serious hunting unless I have a real large diameter broad head on them and better nocks (heavy duty glue on).
I also have some 100LB+ GTs that have 400 Grains up front, 200 grain broad head and 200 grains of 1/4 all thread behind the insert. These weight 800 grains or so and are at about 22% FOC. They fly well at full length out of a SAIII 62#, 29 to 30 inch draw and could be cut down a lot for heavier bows. I found the brass inserts didn't fit well in Gold tips so I went to the all thread trick and it works in easton aluminum and other arrows you can't get brass inserts for. I have a good bundle of weight tubes just sitting there that I took out of arrows, LOL. I also find that the all thread footed arrows are much tougher as well.
And one other thing I've noticed; the arrows with the weight spread out a little up front fly better than ones which have all the weight on the point. I guess that is why footed shafts for wood arrows were developed, after all they could have just made heavier points. By this I mean the arrows with some weight behind the insert so that the weight is spread out to three or more inches. .