Forster Products Neck Tension Gage Features The Forster Neck Tension Gage is built as a simple inspection tool that quickly and accurately screens a batch of .308 caliber brass before it goes through the bullet seating operation. By inserting the stepped end of the tool into a sized case neck and sliding it in until one of the four etched diameters achieves a slip fit reloaders can determine the actual inside neck diameter of each case. That information helps fine tune neck tension for consistent repeatable bullet release during seating which directly affects velocity consistency and accuracy. Each of the tool s four stepped diameters increases in size toward the handle with the exact measurement etched into the metal for easy reference. Beyond measuring neck tension the gage also allows reloaders to inspect the inside diameter of case necks to confirm that a donut has not formed at the neck to shoulder junction a defect that can affect bullet seating and accuracy if left unchecked. Using the gage after sizing and before seating turns an otherwise invisible variable into a measurable controllable step in case preparation. Though offered here in .308 caliber the Neck Tension Gage design is also available in four other calibers for reloaders running multiple cartridges. At just 0.11 lbs this compact tool gives .308 reloaders a practical way to sort and fine tune brass for consistent results at GrabAGun. Forster Products Neck Tension Gage Specifications Manufacturer: Forster Products Model: Neck Tension Gage Caliber: .308 Cal Type: Case Neck Gauge Weight: 0.11 lbs Available At: GrabAGun