he self-contained metallic cartridge is one the most significant innovations in the history of firearms. It consists of four items—brass, bullet, powder, and primer**. Any recent graduate of a hunter-ed program should be able to rattle off this information because illustrations showing the component pieces of cartridges have been a part of the curriculum for decades. What our bright-eyed new hunter might not know is that all four have a profound effect on cartridge performance, whether we’re talking about accuracy, reliability, or lethality. And not to pick on the poor kid, but he or she probably doesn’t have the slightest clue as to what a primer actually does. In this, our young hunter isn’t alone. Of the four building blocks of a cartridge, the primer is the least understood by a long shot. On top of this, a major advance in primer technology promises to make today’s good ammo even better.