Summary

Here is a simple crossbow that can shoot matches. All design credits go to Vince Iacovelli, I am just posting it.
EDIT 8/7/14: Added the STL of the metric file (in mm)

Instructions

Use two hair clips and glue them between the small plastic pieces with the groove facing up. Wrap wire around the ends of the small plastic pieces as shown in the picture. Attach a string to the tips of the hair clips.
When finished, draw the string back to the notch and lay a match on top of the cut-out.Lift string up to fire.
Picture shows wrist strap taped to the handle for comfort.

Matches Crossbow v1