The .220 Swift Modified Case is specially engineered to work with Lock-N-Load Precision gauges for accurate cartridge measurement and reloading precision..220 Swift caliber modified caseFine thread attachment for Lock-N-Load Precision gaugesPerfectly square alignment ensures precise chamber positioningRounded neck opening allows effortless concentric bullet placementStandard diameter bullet compatibilityEssential for precision reloaders seeking the most accurate cartridge measurements and consistent results in .220 Swift ammunition preparation.