PTG Go Gauge Belted Magnums, 300 Winchester Magnum, 7mm Remington Magnum, 338 Winchester Magnum, 458 Winchester Magnum (.535" Base)

The PTG Headspace Go 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. These Go Gauges represent the lower limit of SAAMI specifications for proper headspace dimensions. If the action closes with this gauge is inserted, then the firearm is within acceptable minimum headspace dimensions. This is a Go Gauge only. Both a Go Gauge and a No Go Gauge are required to properly headspace a barrel. N