None of this is confirmed, but rather an interpretation. All carryable items are digitized (thats why you can pull a sparrow out of your pocket). Its futuristic scifi tech that allows you to 'spawn' an object out of data. There is a whole lot more wrong with most weapons, how come a perk can suddenly make heads explode, or increase magazinesize (especially silly with handcannons with fixed chambers to hold the bullets). Its because the weapon you hold is only a physical representation. Its isnt an actual gun, its more or less a program with variables. The way it looks and handles is just for aestethetic purposes and guardians handling a weapon they know. So it doesnt matter if the barrel is aligned with the hammer and all, its there so it represents a gun, but has no actual function unless used as such (like the last word). This also explains why most guns can shoot an element (you couldnt explain that in real world physics either). Also why an old looking weapon like No Land Beyond functions as well as the more futuristic looking weapons like mythoclast. Tl;dr, the explanation still is just space magic.