As a practical matter, most of us will never have to fire our weapons in defense of our homes or loved ones. Even so, if we got a weapon for home defense or personal protection, we'll be loading some kind of appropriate self defense ammo. That ammo is pretty expensive compared to plain FMJ practice rounds. You might run a few expensive magazines of the defense ammo to check feed and function. After that you'll just keep the defense ammo for defense. Which brings me to my question: How long can you keep a couple magazines filled with defense ammo without risking a malfunction? And a related question: What can you do to extend that shelf life?