FEATURES:-For bottleneck cases to be fired in bolt-action rifles only-specifically, cases fired out of a specific rifle & neck-sized to go back into the same rifle-The set consists of a Neck Sizer Die w/ an Expander-Decapping Unit, & a Seater Die w/ Bullet Seater Plug-The Neck Sizer Die resizes the neck only & de-primes-The included Seater Die has a built-in roll crimper to secure the bullet at the same time it's seated-.243 Remington