The 577-500 #2 Express ( 500 #2 Express)Die set consists of Full length size die and Seating die.Designed for 510 BulletDie Body is 1"Die Bushing may be requiredShellholder required # 577 in special shellholder categoryShellholder sold separatelyDo you need ? -Special ShellholderDie BushingUnprimed Brass