The RCBS Hand Case Neck Turner is designed topeel the brass from the outside of your case necks to a consistent thickness. Most commercially available brass has variances in the case neck thickness. This leads to case neck concentricity and bullet runout issues. Truing up the neck cases produces more consistent and accurate hand loaded ammunition. The cutter portion uses caliber specific pilot/mandrels (sold separately) to guide the case neck.Features:- Pilot for use with RCBS hand held case neck turnerSpecifications:- Caliber: .27