Some dies sets permit total reloading with 3 dies. Other individuals may perhaps demand a fourth die for the taper crimp. Taper crimping, in lieu of roll crimping, must generally be finished Using the 9mm. There was a huge dialogue on below decades ago about this, a lot of professionals https://9mm-projectile20730.bloggazza.com/35286946/5-simple-statements-about-9mm-reloading-explained