RCBS Full-Length Die Sets are expertly machined from proprietary die steel to exacting tolerances, followed by a meticulous finishing process to provide hand-loaders with the best dies on the market. Each set includes a Full-Length Sizer Die and Bullet Seating Die, designed specifically for reloading bottleneck cases. The Full-Length Sizer Die features an Expander-Decapping Unit, sizing the case to SAAMI minimum cartridge dimensions while de-priming and expanding the neck to properly accept the bullet. Venting in the die prevents damage from trapped air and excessive lubricant, ensuring smooth operation. Headspace is maintained to tight tolerances to preserve case body length during the sizing process. The Seater Die includes a Bullet Seater Plug and a built-in roll crimper, which secures the bullet as it's seated, providing consistent and reliable ammunition every time.