The 9mm and 380 are two popular ammunition used for different types of firearms. But because they have balls of the same diameter, many don't know if they are the same or interchangeable. The most noticeable difference between 9mm Ammo and 380 is the length of their scales. The 380 is significantly shorter than 9mm, and you can quickly tell them apart at first glance.  9mm Vs. 380 Ammo...