Lock-N-Load� Bullet Comparator Measuring cartridge lengths across the bullet tips is not a reliable (or repeatable) method for measuring your loaded rounds. It�s common for variations of up to .025″ to exist from one round to the next. Our Bullet Comparator solves that problem by measuring rounds from a reliable surface on the bullet� the ogive� to provide consistent, precise measurements of your rounds. The Bullet Comparator is also used to check uniformity of bullets from base to ogive. Optional Anvil Base attaches to the caliper blade for this purpose: HAB1 ANVIL BASE. Our Bullet Comparator easily attaches to the blade of your caliper with a thumbscrew and uses interchangeable insert bushings to measure from the bullet ogive. These bushings are available in fourteen sizes from .17 caliber to .45 caliber. Used in conjunction with the O.A.L. Gauge, the Bullet Comparator provides the ultimate in precision measurement. The Bullet Comparator will properly align the O.A.L. Gauge for precise measurement using your caliper. This method allows direct comparison of your loads as you set up your bullet seating die for any selected bullet free-travel (jump). Includes Comparator body and 6 bullet inserts for bullet diameters: .224″ (5.56mm), .243″ (6mm), .257″, .277″, .284″ (7mm), .308″ (7.62&8mm)