I always tune the arrow to the bow by weight. When I get a new size of arrow I go out and shoot 80,100 and 125 gr. points and see witch group the best at 50 yards. On my 400 axisout of 70 lbs and 28 inch draw 80's shoot OK and 100's group the arrow on top of each other and 125 my group reallyopen up. My 100 gr. Montec really group great at 50 yards' I can shoot them into a 3 inch spot all day long and for deer hunting the blow through the bucks I have shot like they are a card broad box and stick the arrow in the ground. Shota mature buckthis year at 25 yards in the paddle bone on exiting. It passes through and still stuck the arrow in the ground with no damage to the arrow.