Lymans msr precision die systems are the only die sets engineered specifically for msr ammo and are a must for anyone reloading for a modern sporting rifle.Die features ammo checker cartridge "go" gauge included with each set, small base size die for smooth chambering, separate taper crimp die for tight bullet grip and packed in a sturdy, clear cover storage case.Type: 3-Die SetCaliber: 300 BlackoutDie Type: Size/CrimpIn Set: 3