RCBS Full-Length Die Sets are precision-machined from proprietary die steel to exacting tolerances and undergo a meticulous finishing process to deliver the highest-quality dies on the market. Designed for reloading bottleneck cases, each set includes a Full-Length Sizer Die and Bullet Seating Die. The Full-Length Sizer Die features an Expander-Decapping Unit and sizes the case to SAAMI minimum cartridge dimensions, while also de-priming and expanding the neck to accept the bullet. Venting in the die prevents damage from trapped air or excess lubricant. The die holds headspace to minimum tolerances to maintain case body length during sizing. The Seater Die includes a built-in roll crimper that securely seats the bullet while ensuring a tight, consistent crimp for dependable performance with every round. Perfect for reloaders seeking precision and reliability in their reloading process.