I go through quite a few bullets getting it just right. I crimp it down until it will drop into a chamber gauge smoothly. I then pull the bullet to make sure the bullet isn’t pinched at all. I’m looking for a smooth scratch pattern all the way around the bullet with no tapering in the jacketing/plating and no “waist” where the case mouth was. Next, I push the bullet against the bench to make sure it won’t set back in the case under a moderate amount of pressure. I’m not too worried about the bullet walking out of the case under recoil in a semi-auto. That’s mostly a revolver problem.