535 Just remember not to overthink this thing. In the same way I can study ballistics, barells, bullets, for months at a time, spend a fortune on a tack driving rifle and kill a deer at 100 yards, I could have also bought a 30 year old 30-06 and picked up a box of ammo at wally world and easily done the same thing. I see you're new at bowhunting, and by all means if you have and interest/passion for these things pursue it, there's good info above, but remember most of us bowhuters do not own a spin tester. Shoot quality arrows, heads, flex them, shoot them, pick out the better ones and you'll do fine.