So, I have been looking around forums. Weapon designs, and the grimoire cards, and I think I figured out what the heck the ammo in destiny is, and why there are things such as you firing one shot, reloading, and only being down one bullet. I also figured out how you use the same ammo type for different weapons and why swords need ammo. It started when I read the grimoire card for glimmer. It says that glimmer is programmable matter, able to change to practically anything. I think that the ammo we use is a specialized form of glimmer. When you reload, the ammo clip comes off, goes off screen, then a replacement comes on. I think it is the same ammo clip, being reloaded with more programmable ammo from a store on you. The computer in the gun changes it into the ammo the gun uses. We know the guns have electronics in them from a quote by Saladin explaining that SIVA took over the electronics in the iron Lords guns. It also explains why the guns are designed and work in ways that may not make logical sense. I remember a post complaining about the placement of the ammo clip compared to the trigger in scout rifles and the fact that the handcannon firing pin hits the center, despite more than one bullet being in the chamber. This also explains the different bullet shapes despite each gun type getting the same thing to feed it. Also, the swords are just hilts without ammo, but the ammo can transform into matter to make up the blade. This is just my opinion on what is happening in our favorite peashooters based off of very casual research. Let me know what you think! Edit: just some typo fixing and breaking up the wall of text to make it easier.