Gives accurate, comparative readings on actual barrel throat erosion for all M1, M14 and M1A .30-06 and 7.62mm Nato, High Power Service Rifles. Insert in empty chamber and take reading every 1,000 rounds to accurately measure and track barrel throat erosion. Mfg: Ara- Mor SPECS: Steel. Approximately 4" (10cm) long. Includes .30-06 and .308 chamber spacers and complete instructions.
