Full-length die sets for bottleneck cases include two essential dies. The Full-Length (FL) resizing die contains a decapping rod assembly with a neck expander (size button), which resizes the entire case and removes the spent primer, while ensuring proper neck tension for bullet seating. The seating die (ST) features a bullet guide, a built-in crimp ring and the correct seating plug, enabling precise bullet placement and secure crimping. Together, these dies ensure accurate resizing and reliable bullet seating, essential for achieving consistent, high-quality reloading results.