EGW 4-Hole Chamber Checker Max Cartridge Gage (9mm Luger, 38 Super, 40 S&W, 45 ACP) This is a one-piece, non-adjustable gage for checking factory and re-loaded ammunition to ensure fit Has four chambers, one chamber for each of the following cartridges: 9mm Luger, 38 Super, 40 S&W, 45 Used to compare cartridges against the SAAMI chamber dimensions Drop a loaded round into the gage.