One of things to consider about using SS Pins is the pins, in tumbling the process actually changes the profile of the metal. This is a microscopic change, but it does occur.

When working the profile of the metal was important to the adhesion of coatings.  Yes, I realize we are not concerned about coatings in this game.

It will change, imho, the feel of primer seating, the ability for the primer to pass a bit of gas.

I also realize people have "been doing it that way for years" but it is something to consider.

MarkTrew