Chamber / Case Length Gauge Features RCBS Chamber Case Length Gauge 243 Winchester - The RCBS Chamber / Cartridge Gauge is a one-piece non-adjustable gauge designed to check all critical dimensions of ammunition to insure proper fit. Quickly check case length diameter and the overall cartridge length of your handloaded ammo. Simply drop a loaded round into the precision-made gauge and if your cartridge fits the gauge it ll fit your pistol. Gauge checks both chambering as well as cartridge length. Chamber / Case Length Gauge Specifications Primer Size: Large Rifle Reloading Case Prep Type: Case Length Gauge Reloading Diameter: .243 Quickly confirms ammunition will fit your pistol s chamber Easy-to-read engravings display caliber size Quickly check case length diameter and the overall cartridge length