The RCBS Flash Hole Deburring Tool is a great tool for any reloader who is looking increase the consistency and reduce variations from case to case to get the best possible accuracy out of their shooting equipment. When brass is manufactured there are burrs that are sometimes created when the flash hole is tapped out. This process only needs to be done once for the complete life of a piece of brass. These caliber specific pilot stops are designed to be used with the caliber listed in the description and are made to prevent the removal of too much brass from the end of the flash hole.