Which shotgun shell primer have you found to be the most sensitive. In other words, if you had a gun that was striking the primer lightly, what primer would you prefer?
I guess if you say it's so, then it must be true.One thing I can say is no one has any information on which primer has the softest metal on the strike face. Whether it's brass or steel, it has no bearing on the question as both can be made harder or softer with alloying. They all are about the same.
I'm not a metallurgist either but the answer to the OP's question calls for the expertise of one. And you guys with the weak springs should stop trying to solve that problem by looking for primers with strike faces that are softer than others. And the answer to that question does not depend on whether the strike face is made of ferrous or non-ferrous metal as both can be made as hard or as soft as one likes.Not a metallurgist so would not really know if they were made of copper, aluminum or jell-o, but again Winchesters go boom when trigger is pulled, others, not so much. Read what you want out of it, only trying to help. Happy Hanukkah.