Seems that no one makes case gauges for anything other than .223 Remington, .308 Remington, and 30-.06. Any one know where to get a case gauge for .303 Savage, .303 British, 6.8 SPC Remington? Seems that would make reloading safer due to no headspace issues but no one sells them. Redding says the best gauge is the rifle chamber but that is not always easy to see in an AR configuration rifle. Thoughts?