Why are some 3-blade broadheads inaccurate?
The design of some 3-blade broadheads is not conducive to accurate shooting with a crossbow. Some broadheads have extremely large surface area, blade shape, or other design characteristics that, when used on an arrow shaft of 20″ or less, will not fly well. The shorter the arrow you are shooting, the more difficult it is to get extremely tight groups with some broadheads. If the heads have too much surface area or a very large cutting diameter, they will plane easily from catching air in flight.