I weigh my cases only for the reason to obtain case capacity. Weigh case. Notate weight. Fill with alcohol and weigh again. Use case weight to subtract from gross weight and you have case capacity in grains. That is what matters in my opinion. Case capacity directly effects pressure and therefore effects velocity. The closer case capacity is the more those cases will be consistent when used with other techniques. And I trim all brass before weighing. Remove all variables to obtain more consistency.