I use 85 grain heads only because my arrow are shorter 28 3/4 inch and I use smaller vanes. 4 inch vane will control any broadhead out there on carbon arrows. Foc is very important to me. the longer the arrow and the heaver your vanes the heaver the point. Keep your F.O.C. at around 11 % are I like a little less mine are at 9 % because they group better for me. You will get better groups at longer yardage. 40 years ago 125 or 140 were used a lot becuase of long arrows, 5 inch feathers and heaver nocks. With 400 axis I would stay with no more than 100s. F.O.C. is very important for good shooting keeps the arrow behided the point, not following the point down and hitting your target with the tail up losing energy as it bends forward