Neck die sets for bottleneck cases consist of two carefully engineered dies to ensure precise reloading. The neck (NK) resizing die is equipped with a decapping rod assembly and a neck expander (size button), which work together to resize the case neck accurately, ensuring proper tension and fit for the bullet. The seating die (ST) includes a bullet guide, built-in crimp ring and the appropriate seating plug, enabling smooth bullet seating and a consistent crimp. These features combine to offer reloaders reliable and high-performance results when working with bottleneck cases.