The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 – This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety. Mfg: Forster SPECS: Machined Steel. Size varies with caliber and gauge style. NOTE: Gauges Interchangeable between calibers have same Stock #. .30-30 Cartridges are .219 Wasp, .219 Zipper, .22 Sav HP, .30-30, .32 Win Spl, .32-40, .375 Win and .38-55. .30-06 Cartridges are .25-06, .270 Win, .30-06, 8mm-06
