The Forster Forster 30-30 Winchester No-go Gauge is an essential tool for gunsmiths and firearm enthusiasts ensuring precise chamber headspace measurements Designed for a wide range of cartridges including the 22 Savage High Power 219 Donaldson Wasp 219 Zipper 32 Winchester Special 25-35 Winchester 7-30 Waters 30 Herrett 303 Savage 30-30 Winchester 307 Winchester 32-40 Winchester 356 Winchester and 375 Win this no-go gauge helps maintain optimal firearm performance and safety by preventing over-chambering and potential misfires Ideal for maintaining the integrity of your firearms and ensuring reliable operation the Forster Forster No-go Gauge is a must-have for any serious gun maintenance toolkit