When working on older firearms, it is important to check the hardness of the metal to insure the heat treatment of the metal has not been compromised. In this GunTec presentation Larry Potterfield, CEO and Founder of MidwayUSA, uses a Rockwell hardness tester to test the hardness of a Mauser 98 bolt and receiver. The process is quick and easy, requiring only that one zero the machine, place the item to be tested on the work piece support, engage the penetrator, and check the reading. The results of the test are given using the Rockwell C scale. By checking a bolt or receiver after performing work on them, you can be sure the parts are safe to use.