I assume that your purpose in looking at a 1.500 max case length 6PPC reamer is that you want to minimize the gap between case necks and the end of the neck portion of the chamber. Before you go any further, please watch the six segments of Jack Neary's presentation on Youtube. Just go to the Youtube main page and type in his name. I would tell you that your assumption about the advantage of this approach is incorrect, but rather than hear it from me, I think that it should carry a lot more weight from Jack, which is as it should be. Over ten years ago, I believe that Tony Boyer tried this approach, and when I had the chance to talk to him in a brief phone conversation, I asked him if he had found any advantage to it. He told me that he had not. Come back and tell us what you think after watching the segments of Jack's presentation.