Some dies sets let total reloading with 3 dies. Other folks could need a fourth die to the taper crimp. Taper crimping, as an alternative to roll crimping, really should normally be done with the 9mm. The under photographs and facts are from a super in-depth publish from Lucky Gunner https://9mmcase97318.livebloggs.com/44637943/reloading-9mm-for-dummies