Man, I love Overwatch so much. I was using Reaper in the gameplay and yea his reload animation is pretty weird. He does indeed just drop them and new guns magically appear. Overwatch doesn't push itself to be realistic, that's for sure. I think that's okay though.
Lucky for me, I have so many cosmetic items that transferred from the old game that I won't need to purchase anything new. It does kind of suck to never be unlocking new stuff though unless you want to pay for the battle pass.