The RCBS .17 Caliber 3-Way Pilot/Chamfer was designed specifically for use with your RCBS Case Trimmer, intended to provide reloaders like you with an easy way to change the caliber of the trimmer. This caliber-specific pilot/chamfer is intended for use with .17 caliber cases. Not only is this RCBS 3-Way Pilot/Chamfer caliber-specific, but it helps to save you a great deal of time and hassle in the reloading process, because it has a unique 3-blade cutter head that trims cartridge cases in the same manner as a standard cutting head while also chamfering and deburring.