A spontaneously immortalized human kerazinocyte cell line is disclosed. The boring tool comprises a tool body, a plurality of replaceable cutting inserts and an insert locator. Next, the process cuts the phase shift regions in selected ones of the cutting areas to define phase shift windows, and assigns phase values to the phase shift windows. The sighting device may also include a mechanical sight that functions as the rear mechanical sight on the gun andor a secondary light source. The apparatus and method may be employed as a stand-alone unit or as part of another device pursuant to the many applications described herein.