Forster Products has a long history of excellence since 1935, with a reputation as a top supplier of quality Reloading and Gunsmithing Tools. This Field gauge is manufactured from top-quality, hardened steel and precision ground to American National Standards Institute SAAMI tolerances. Ground to an exacting ±.00015″ headspace tolerance to ensure accurate testing of a rifle’s chamber, this precision-engineered tool delivers the reliability gunsmiths and shooters demand.
The FIELD gauge corresponds to the longest safe headspace, and if a rifle closes on a FIELD gage, its chamber is dangerously close to, or longer than, SAAMI-specified maximum chamber size. FIELD gages are slightly shorter than the SAAMI maximum in order to give a small safety margin. This makes it an essential diagnostic tool for evaluating the condition of classic 30-40 Krag rifles and identifying potential safety concerns before ammunition is fired.
Forster Headspace Gages are made with painstaking care and exacting manufacturing standards to ensure accurate testing of your rifle’s chamber. Whether you’re a dedicated gunsmith, reloader, or firearms collector, this Field gauge provides the precision measurement capability needed to verify chamber specifications and maintain shooting safety on this classic rifle cartridge.





