SOLD RCBS Case Master Gauging Tool Model #87310 NIB $75.00 + Shipping. Cash,Money Order or Pay-Pal Details: A quick, convenient way to determine several important case and cartridge dimensions. The CaseMaster® gauging tool measures case neck concentricity, uniformity and thickness, as well as case length and bullet run-out. All are important to accuracy and safety. Detects case head separation before symptoms are apparent on the outside of case. Much quicker than a dial caliper and makes a tedious job simple and less tiring.