RCBS Full-Length Die Sets are crafted from proprietary die steel to precise tolerances, followed by a meticulous finishing process to ensure the highest quality for hand-loaders. Each set includes two essential dies: a Full-Length Sizing Die and a Bullet Seating Die, designed specifically for reloading bottleneck cases. The Full-Length Sizer Die features an Expander-Decapping Unit that sizes the case, de-primes and expands the neck to properly accept the bullet. Vents in the die help prevent case damage caused by trapped air and excess lubricant. The die maintains precise headspace tolerances to avoid altering the case body length during full-length sizing. The Bullet Seating Die includes a built-in roll crimper, ensuring the bullet is securely seated while maintaining consistent performance.