Not any one real reason. When you get a panic,you get people deciding that their current inventory is too small. This causes a shortage. Other folks try to capitalize on this shortage by buying up whatever they can find and sell it at inflated prices. Then normal consumers start to run out. Now nearly everyone is reevaluating their inventory level. Everyone who runs across ammo at quasi-reasonable prices will buy it. In order for thing to return to normal, everyone needs to get stocked up at their new higher inventory levels.
