The vampire stake is just about the deadliest "slingshot" projectile I ever made. When fired from my 7 ft. crossbow, it is plain lethal.
But it had two drawbacks.
First, the "hooks" were made from plywood and broke off when they hit something, like the edge of the catch box or so.
Second, the wooden tip went blunt quickly.
So I replaced the wooden hooks with solid 6mm aluminum, and also I drilled the tip out and glued in four inches of 8mm threaded rod, sharpened the tip to a needle point.
Will shoot at things tomorrow!