Neck die sets for bottleneck cases consist of two essential dies designed to ensure precise reloading. The neck (NK) resizing die features a decapping rod assembly with a neck expander (size button), which resizes the neck of the case while decapping the primer. The seating die (ST) includes a bullet guide, a built-in crimp ring and the appropriate seating plug to securely seat the bullet and apply a proper crimp. These neck die sets are ideal for achieving the accuracy and consistency required for bottleneck cartridges, ensuring your reloading process is efficient and reliable.