The Hornady Lock-N-Load Modified Case for .45-70 Government cartridges is specially engineered to work with Lock-N-Load Precision gauges for accurate firearm measurements and reloading setup.Hornady Lock-N-Load .45-70 Government Modified CaseSpecial fine threading for secure attachment to precision gaugesPerfectly square alignment ensures precise chamber measurementRound slightly opened neck allows standard bullets to slip in concentricallyDesigned for use with Lock-N-Load Precision gauge systemsEssential for precision reloaders and gunsmiths who demand accurate measurements for optimal cartridge overall length and bullet seating depth in .45-70 Government firearms.