The important issue is that you resolved the problem.I had read the instructions and watched the video, however I will not use something until I’m certain about how they are working. I knew that they included the shims and said that they could be used, but until today I was not certain how they would modify the headspace setting. I took the die apart on a table in front of me and it struck me how they would do what is advertised. Then I put them to the test and they worked. I need to know how something works, before I will use it. This die is not the same as most sizing dies out there and until today, I was not certain how each of its features operate. I’m very happy now though! You are definitely right about reading the directions though.
I too would have been confused by that die function, never seen one that functions that way. In the past I have by passed reading instructions on something that I was familiar with and most of the time I got away with it. But a few times I got burned so now I discipline myself to read the instructions first.