Headspace is a critical component of firearm safety and is easy to measure when you have the right tools. Larry Potterfield, CEO and Founder of MidwayUSA, uses a Mauser 98 rifle in this video to demonstrate the process for checking headspace. He starts by taking the bolt out of the action and removing the extractor. Headspace is then checked using a Go and No Go gauge. He starts by inserting the go gauge into the chamber and gently closing the bolt. If the chamber has at least the minimum amount of headspace the bolt will completely close. Now he repeats the process using the No Go gauge. If the headspace is excessive then the bolt will close completely and the gun shouldn't be fired.