A way to avoid not charging a case when batch loading with a single stage is real simple. Put the uncharged cases in a bowl. Take the case out turn it upside down, then turn upright. Place the funnel on the top, charge with a powder measure, or dipper. Place the charged round into a loading tray. Repeat till the loading tray is filled, or you run out of cases.
Before seating a bullet look inside the case before putting it in the press.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.