RCBS - Precision Mic. - 338 Winchester magnum

A few twists of the Precision Mic and you'll know your chamber headspace and bullet seating depth to 0.001 of an inch. Precision Mic measures from the datum point on the case shoulder to the base, giving you spot-on ANSI/SAAMI tolerance readings. An indispensable tool for safe, accurate loads that extend the life of your brass and rifle.