I can only guess that you have years and years of very valuable knowledge that everyone here would love to get your imput on.
Egg, you should get a lot of likes on that one. And then there are those that feel threatened. In the big inning of the Internet reloaders were claiming the shell holder and die manufacturer had to match. I should not have to remind you but reloaders in the beginning of the Internet never measured the deck height of the shell holder and then one of them decided he invented the term 'deck height'.
Paper does not last as long as plastic but at the time I had a paper box packed by C&H of El Monte, California; they printed the instructions of the bottom of the box identified as a counter display. The instructions on the bottom of their box claimed the dies in the box were designed to be used with a shell holder with a height of .125". From the big inning reloaders were grinding the bottom of the die and or top of the shell holder when they did not understand what was going on. I have always suggested grinding the shell holder and or die was never necessary.
Anything that can be accomplished by grinding can be accomplished with the feeler gage and you have no ideal how angry that made reloaders, all of them. I did have one moderator remove my post claiming he did not want my advise getting someone killed. In about 6 months he did a cut and paste of my response and claimed it as his ideal. And he finished with, "No biggie".
And now someone is claiming he cut a groove in a shell holder and you did not ask him what shell holder? You did not say "some do and some don't, Why?"
F. Guffey