Outside Neck Turner Pilot (.171 Diameter) by FORSTER RELOADING PRODUCTSPilot for Outside Neck Turner #17 and for .171" diameter bullets. Must be used with 17 caliber Cutter Shaft (p/n CT1010-CTC417 and 17 caliber carbide cutter p/n OT1010-012.17) Pilots (Mandrels) for your Forster Outside Neck Turner. Standard pilots are .0020" - .0025" smaller than bullet diameter.