Forster Products manufactures precision headspace gauges to maximize safety and accuracy in your rifle. These gauges are necessary when finish chambering a barrel, or when checking the chamber of a used gun to be sure the headspace dimensions are within safe limits. Machined from A2 tool steel, these gauges are held to tolerances within 0.00015" to ensure accurate testing of your rifle's chamber.Notes:Headspace standards are set by SAAMI (Sporting Arms and Ammunition Manufacturers Institute) specifications.Headspace is measured from the bolt face to one of four locations, depending on the cartridge used. The measurement is taken from the rim of rimmed cases like the .30-30, or the shoulder of a necked case like the .30-06, the case mouth of a straight or tapered case like the 30 Carbine, or the belt of a belted case like the .300 Winchester Magnum.Headspace gauges are available in three different lengths, listed below, from shortest to longest: Go Gauge: Go Gauges match the min...