The Hornady Lock-N-Load .224" - .308" Comparator Set measures the ogive to produce consistent, precise measurements of your rounds, as well as check for bullet uniformity. The comparator body includes 6 bullet inserts for diameters .224" (5.56mm), .243" (6mm), .257", .277", .284" (7mm) and .308" (7.62mm and 8mm). Hornady Lock-N-Load .224-in - .308-in Comparator Set - Reloading at Academy Sports