Confused; are you shooting these with the adapters, like the other heads, or just the BH, so the total head weight is only slightly heavier than your previous set-ups? If you added that heavy a head to the adapters, you have a much heavier head now, so you have radically changed the dynamic spine of the arrow, probably making it too weak to shoot with broadheads, although you might get away with it if you just had field points on there. Have you checked the BH alignment? If there is any wobble when you spin them on a flat surface, they aren't true, and will not shoot, even if the spine is correct. These are just two possiblilites. Paul.