Some dies sets permit entire reloading with three dies. Many others may perhaps require a fourth die with the taper crimp. Taper crimping, in lieu of roll crimping, should always be performed With all the 9mm. Good day, I live in S. CA and just lately purchased my 1st pistol, https://cristianarmzm.tokka-blog.com/37115541/the-2-minute-rule-for-reloading-9mm-ammo