The Hornady Lock-N-Load 40 S&W Cartridge Gauge is an essential tool for reloaders to verify proper case and ammunition dimensions for SAAMI chamber specifications.Hornady Lock-N-Load 40 S&W Cartridge GaugeEnsures correct fit in SAAMI standard chambersChecks both cases and completed ammunitionPrecision-machined to exact specificationsEssential quality control tool for reloadingPerfect for handloaders who demand precision and safety this gauge helps ensure your 40 S&W cartridges will chamber properly and function reliably in any firearm.