This two-die set is designed for reloading bottleneck cases and includes a Full-Length Sizer Die with an Expander-Decapping Unit as well as a Seater Die with a built-in roll crimp. The Sizer Die brings the case down to SAAMI minimum cartridge dimensions de-primes and expands the neck to accept a new bullet. Its internal vents help prevent case damage from trapped air or excess lubricant while precise headspace control minimizes changes to case body length during full-length resizing.Paired with the Sizer Die the Seater Die seats the bullet and applies a secure roll crimp in one step ensuring consistent reliable performance. Each die set is made with proprietary die steel and has a standard 7/8"-14 thread fitting most common reloading presses. Shipped in a green die box and manufactured in the USA for 30-30 Winchester this set offers an all-in-one solution for producing accurate precision-loaded ammunition. Order yours online today!Shop more reloading supplies here!