Some dies sets make it possible for full reloading with 3 dies. Many others could require a fourth die with the taper crimp. Taper crimping, in lieu of roll crimping, ought to often be accomplished with the 9mm. The below images and info are from a super in-depth put up https://reloading-9mm-ammo29628.creacionblog.com/36093651/5-simple-statements-about-9mm-reloading-explained