The RCBS 87580 is a decapping die that serves to swiftly remove primers from cases before they undergo a cleaning process. It can manage most cases ranging in size from .22 to .25.This product comes in a two-die set that\'s primarily used for reloading bottleneck cases. The set includes a Full-Length Sizer Die equipped with an Expander-Decapping Unit and a Seater Die with a Bullet Seater Plug. Each piece plays an integral role in the reloading process.The Full-Length Sizer Die adjusts the case to SAAMI minimum cartridge dimensions. It not only sizes the outside of the case but also de-primes and expands the neck to accommodate the bullet. This die features vents that prevent case damage due to trapped air or excessive lubricant. It maintains headspace to the minimum tolerances to prevent the alteration of the case body length during full-length sizing.The set also includes a Seater Die that comes with a built-in roll crimper. This feature helps to secure the bullet as it\'s seated. The caliber of the die matches .204 Ruger, and it follows the standard 7/8-inch-14 thread.