In this video, Larry Potterfield, CEO and Founder of MidwayUSA, explains the process for measuring the amount of firing pin protrusion on a bolt action rifle using a model 98 Mauser. He starts by removing the bolt from the action and dropping the striker so the firing pin protrudes through the face of the bolt. Using a firing pin protrusion gauge made by Baker, he zeros the gauge, places it on the bolt face, and tightens the locking screw. Using a pair of calipers he then measures the gauge and subtracts the width of the gauge at zero from the new measurement. The number left is the exact amount of firing pin protrusion.