The most important thing to worry about is case volume. Full length size and trim each case then weigh each case separately and record the empty weight, then fill with water and weigh again. Subtract the full weight from the empty weight and that will give you the volume of each case. Separate the cases into groups that weigh out within .1 grain and load those for accuracy. Get your self a large medicine dropper to fill the cases with water and use a credit card to scrape off the excess so that the water is even with the case mouth.