WBR — real hard to say from here. Is it the shorter arrow, or the broadhead vs. field point that’s improving flight? Did you notice any wobbling etc. with the field points? Some archers prefer longer arrows, one advantage being better FoC, while others prefer to cut them just long enough so as not to have the visual distraction of the extra shaft sticking out. Also, for those with target panic a shorter arrow, at least with a broadhead, let’s you know when you’ve reached full draw without a clicker. But you’re not asking any of that. If it were me I would replace the broadhead on the shorter arrow with a field point of the same weight and see if it still flies better than the longer ones. If so, I’d cut off another to be sure it’s consistent before chopping them all off. With luck someone here with far more experience in this realm will come to your aid. dp
