Measuring cartridge lengths across the bullet tips is not a reliable (or repeatable) method for measuring your loaded rounds. It is not uncommon for variations of up to .025" to exist from one round to the next when measured across the bullet tips. Bullet tips vary considerably due to the way in which bullets are made. Hornady's Bullet Comparator solves that problem by measuring your rounds from a reliable surface on the bullet – the ogive – to provide consistent, precise measurements of your rounds. The Bullet Comparator is also used by many shooters to check uniformity of bullets – from base to ogive – which is critical to accuracy.
When used in conjunction with the OAL Gauge, the Bullet Comparator provides the ultimate in precision measurement. The Bullet Comparator will properly align the OAL Gauge for proper, precise measurement using your caliper. This method allows direct comparison of your loads as you set up your bullet seating die for the correct bullet free-travel (jump).
This Basic Set Includes the comparator body (Caliper NOT included) and 14 bullet inserts for bullet diameters: .172," .204," .224" (5.56mm), .243" (6mm), .257," .264," .277," .284" (7mm), .308," .338," .358," .375," .416," .458".