K&M - Custom Gauge Pin Size:0.2015 allowing gas to blow rearward

allowing gas to blow rearward like rocket exhaust

At the same time it “bumps” the shoulder of the case to maintain excellent case neck concentricity

The Mantis X2 is the most powerful training aid for dry fire only practice

making them 100% brass free and 100% barrel safe

K&M - Custom Gauge Pin Size:0.2015 allowing gas to blow rearwardMeasures neck inside diameter Checking your Case Neck with Gage Pins: After expanding use the corresponding gage pins to confirm the neck sized as expected. The feel you are looking for is a light drag on the gage pin. When sized properly the gage pin will act as a piston as you push the pin into the case neck while holding your finger or thumb over the primer pocket. You can actually feel the air compress inside the case. Quite often the brass can be