I don't really ever recall seeing it discussed, but there is also a 'fit' issue and I am not speaking of the oversize primer kind of 'fit', rather the way that the primer from brand to brand 'fit' certain hulls. I do not much care for a primer that even slightly protrudes from the case head. With many of today's primer cups being steel, even a slight protrusion will end up making a rather noticable set of vertical marks on the breech face. Used to be that battery cups were non ferris, some still are, but if they are steel .. I want a nice 'fit' meaning flush with the head or just below, thank you.
Remington primers provide a good 'fit' in a variety of modern 209 sized hulls.
