Full-length die sets for bottleneck cases contain two dies. The Full-Length (FL) resizing die features 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) includes a bullet guide, built-in crimp ring and the correct seating plug, providing accurate bullet placement and a secure crimp. These two dies work together to ensure consistent and reliable resizing and bullet seating, optimizing performance in your reloading process.