Simple Caliber Ammo Checker Features Lyman Ammo Checkers are gauges that verify the quality and consistency of both reloaded and factory ammo. They are machined from solid aluminum and cut with custom tooling to SAAMI minimum chamber tolerances. Just drop your cartridge into the gauge and if it fits it will chamber in your gun. Simple Caliber Ammo Checker Specifications Aluminum 6.8 Rem SPC Orange