RCBS Full-Length Die Sets are crafted from proprietary die steel, machined to precise tolerances and undergo a detailed finishing process, ensuring top-quality performance for hand-loaders. Each set includes a Full-Length Sizing Die and Bullet Seating Die, designed for reloading bottleneck cases. The Full-Length Sizing Die features an Expander-Decapping Unit that brings the case to SAAMI minimum dimensions, sizes the case exterior, de-primes and expands the neck to properly fit the bullet. Vents are integrated to prevent damage from trapped air and excess lubricant. Headspace is kept to tight tolerances to avoid altering the case body length during sizing. The Seater Die, with a Bullet Seater Plug, also incorporates a roll crimper to securely hold the bullet in place as it's seated.