The BARREL CHAMFERING PLUG GAUGES are precision tools for measuring the throat diameter of a barrel to ensure maximum accuracy.
They are useful for both preventing over-chamfering during gunsmithing and as a diagnostic tool for firearms with accuracy issues.
The gauges are self-piloted, cover multiple calibers, and are designed to measure chamfers at 11° and 18°, with a special 5° gauge for certain Ruger models.