The front of a rimless bottleneck case has exactly the form and shape as the front of the chamber.
Like a tapered tool pulled into a tapered hole, it should center within ~.0001" at the taper and have excellent axial alignment away from the taper.
The word 'forum" does not mean "not criticizing books."
"Ad hominem fallacy" is not the same as point by point criticism of books. If you bought the book, and believe it all, it may FEEL like an ad hominem attack, but you might strive to accept other points of view may exist.
Are we a nation of competing ideas, or a nation of forced conformity of thought?