Lyman Multi-Caliber Handgun Ammo Checker Cartridge Gauge 380 ACP, 9mm Luger, 38 Super, 40 S&W, 45 ACP, 38 Special/357 Magnum, 44 Special/44 Remington Magnum, 45 Colt (Long Colt)Lyman's Ammo Checkers check the quality and consistency of both reloaded rounds and purchased ammo. A must for any auto shooter for easy and consistent feed. You can't afford misfeeds, so get the easiest "no go" gauge available today! These Ammo Checkers are gauges that allow a reloader to quickly confirm that their ammunition will fit in their chamber. Machined from solid blocks of 6061 T6 aircraft grade aluminum and cut with custom tooling to SAAMI