The gun writers are no different than you and me or other shooters. They do things and and put it down in writing later to find out that there is a better way or the Mag primers and larger flash holes are not the thing. Something they dont find out just shooting a few test loads before writing the article.
I use a mag primer for one caliber but not all. Case length, diameter, bullet weight and compression is not a fixed thing and all will change when the powder manufacture changes a lot as well as the brass or primers.
And above all else the person that has the press handle in his hands or the nut behind the butplate that is mostly the issue.
Kurt
