With the RCBS Pistol Chamber / Cartridge Gauge, you can quickly check case length, diameter, and the overall cartridge length of you handloaded pistol ammo. Simply drop a loaded round into the precision made gauge, and if your cartridge fits the gauge, it'll fit your pistol. Quickly confirms ammunition will fit your pistol's chamber Easy-to-read engravings display caliber size The RCBS Pistol Chamber / Cartridge Gauge is a one-piece, non-adjustable gauge designed to check all critical dimensions of pistol ammunition to insure proper fit. Mfg: Rcbs