The Lyman Pro Ammo Checker for 45-70 Government cartridges is precision machined from corrosion resistant stainless steel to minimum SAAMI chamber tolerances.Lyman Pro Ammo Checker Single Caliber 45-70 GovernmentPrecision machined stainless steel constructionBuilt to minimum SAAMI chamber tolerancesClearly marked for caliber identificationSimple drop-in gauge testingA must-have final check for competitive shooters or anyone who wants to ensure smooth trouble-free chambering of reloaded ammunition. Simply drop your loaded cartridge into the gauge - if it fits it will chamber in your gun.