From the evidence you're providing, I'm willing to bet the problem you are having is 2 fold.
1.) Get rid of the Hornady "One Shot", and get some Dillon Case Lube. There are others that work well, but of all of them that I've tried, Dillon is by far the best.
2.) Your expander plug is over expanding the inside of your case necks. Combined with the lack of lubricity of the Hornady Case Lube = Stuck case and torn case rim. I think at this point a change in case lube, along with being sure to lube the inside of the neck, and a new expander plug, (they are quite inexpensive), and your problems will vanish. Just a tip. When you pick up a new expander plug get several decapping pins with it. They are very inexpensive, and it's good to have several extras on hand. It is very easy to break one if the case or flash hole is misaligned.