Another point of view here. The L-n-L press is one of the best for a variety of reasons, but let's just keep it to priming for now. I have owned and used 3 different presses with automatic priming systems and they all have one thing in common. None of them are set up to seat a primer below flush - and maybe not even flush on a rainy day.
That's how they are designed, so all the dunces out there will not crush a primer whilst they attempt to load 500 or more rounds per hour. Again, NO consumer press that I know of will seat a primer below flush and most get away with slightly above that. Its a fact. You must go through your loaded rounds and visually inspect them for high primers. Then take a Sinclair tool and seat the high ones. But I digress.
Priming is the hardest step to set up correctly on any progressive press. You will never achieve a solid production line operation like the ads tell you. The presses do work great, but you have to pay attention on every priming stroke. Let's say there is nothing bent or damaged. It may take the new user several weeks or more to learn the nuances of his press. Each one is different. There are many small tweaks that must be made before everything is lined up and ready. Of the progressives I have owned, the Hornady is the best of them, including the priming. I discovered that for myself, a 2-step process of priming worked the best.
When the case is ready to prime, the handle is straight up. My method is to gently push the lever forward (GENTLY) whilst observing the empty case. If the case wiggles and stands up straight, I know there is a primer in the slide pushing up under the case. Also, this first step lets the primer and case self-align without the application of sudden force. Only if the case shows me that a primer is present do I then push the handle forward to seat the primer.
The above avoids the 2 main problems with priming. First, it insures that a case actually gets primed, and second it allows the case to line itself up with the primer before you smash everything and have to start over. It works and after I started using this method, I had no further priming troubles. There is ALWAYS an exception and that is the last primer in the tube. Most presses will cough on the last primer. You can experiment with placing a bit more weight on the white primer rod - that part is important and not just there for looks.
WM