broadhead Mechanical or Expandable Blades
Grim Reaper X-Bow Mech Broadhead
These are the up and coming broadheads in the archery world and for good reason. The blade is retracted all the way back until the shot is made, where the blade opens upon impact.
I would only use these with a draw weight of 50 pounds or more because of the power needed for it to upon on impact.
100 Grain Braodhead