Abstract: A reusable breach loading target pressure activated lancet firing device for use with a lancet includes a sled which releasably engages the lancet so that the lancet point may extend outwardly from a distal end of the sled. The sled is substantially contained and movably engaged within a housing having a distal aperture at its distal end and a side aperture defining a breach to allow access to the sled for engaging and disengaging the lancet. A spring is provided for biasing the distal end of the sled toward the distal end of the housing. A cocking mechanism positions and releasably holds the sled in a position in a direction toward the proximal end of the housing so that the spring means is partially deflected. A trigger mechanism for releasing the cocking mechanism and allowing the sled to move toward the distal aperture, also allows the lancet, when engaged in the sled, to project outwardly from the distal aperture.