PTG No Go Gauge Belted Magnums, 300 Winchester Magnum, 7mm Remington Magnum, 338 Winchester Magnum, 458 Winchester Magnum (.535 Base)

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. This is a No Go Gauge only, and both a Go Gauge and a No Go Gauge are required to properly headspace a barrel. These No Go Gauges represent the upper limit of SAAMI specifications for proper headspace dimensions. If the action closes with this gauge inserted, then the firearm may not be within acceptable maximum headspace dimensions and should be examin