Examine completed cartridge cases for cracks.
What does a Mercury Cracking Tester do?
Examines completed cartridge case for cracks: Cleans cases by dipping them in solution of nitric acid and rinsing them in water. Dips cases into mercurous nitrate solution. Heats chemically treated cases over flame and examines cases for discolorations, indicative of cracks. Discards defective cases.