The RCBS 11103 is a two-die set, designed specifically for bottleneck type cases often used in tight-chambering semi-automatic, pump or lever-action rifles. The set is comprised of a Small Base Sizer that comes with an Expander-Decapping Unit and a Regular Seater Die that features a Seater Plug. This sizer is capable of resizing cases below Saami minimums, effectively reducing the shoulder and body by a few thousandths while simultaneously de-priming the case. There is an included Seater Die that boasts a built-in roll crimper. This component allows the bullet to be securely crimped as it\'s being seated into place. For seating bullets with no crimping, you simply have to unscrew the die until the crimp ring is unable to engage with the case mouth any longer.