RCBS Carbide sizing dies are perfect for all straight wall cases, particularly when loading in volume, as they require no lubricant. The carbide sizing ring is extremely hard and also very slick, making stuck cases a thing of the past in all straight walled cases. RCBS pioneered and developed the 3 Die Sets for straight wall rifle and pistol cases. In the 3 Die Set sizing and expanding (belling) are done in separate dies. The 3 Die Set has a Sizer Die with Decapping Unit, Expander Die for expanding and belling the case mouth and a Seater Die with Bullet Seater Plug(s) for seating and crimping the bullet.