A drill assembly for creating a reverse counterbore bone tunnel while increasing bone preservation. The drill assembly including a housing having an actuation mechanism and a cannulated shaft connected to the actuation mechanism. The drill assembly also includes a rigid rod extending through the cannulated shaft. Engaging the actuation mechanism moves the cannulated shaft along the rigid rod. The drill assembly additionally includes a distal tip connected to the cannulated shaft and the rigid rod. Proximal movement of the cannulated shaft along the rigid rod causes the distal tip to rotate from a first configuration to a second configuration. In the second configuration, the distal tip extends at an angle relative to the cannulated shaft.