Actually, I believe that is closer to what's happening than not. Regardless of what it is, we are looking at a sci-fi game where we have been given superpowers by a magic orb in the sky. I think anything is possible. Also, Glimmer in the game is used as currency because of its ability to materialize into different things. Within those weapons the tradition bullet-hammer deal works for weaponry, but those rounds being energy based could change their state and essentially just become a beam of light due to other mechanics inside the weaponry that we don't know about. Glimmer may be a large part in the ammunition production, especially since there are 'ammo synthesis' you can use to create ammunition from a handheld object. How do those work? They are likely glimmer based. At the end of the day it's simply sci-fi.