They are with the limited number of shell models we have that are shared. Not individual unqiue shell models for every single variant of shell in game. Many share common models.
It does with the volumes in every battle fired at any one moment per battle. Again, its one of the key reasons (alongside the actual practicality side of individual shell models) its not that way.
I am sorry I don’t get it. If each casing/shell is rendered after each shot what does it matter if there is only 5 types or if there are more. Sure it’s going to take more VRAM to load the meshes and textures for the different types but the amount of things rendered at once is the same. I bet you could get away with the same texture on all of them and meshes don’t really take much space.
Unlucky but at the same BR there exists MiG-29G with no ARH missiles but an HMD and better IR missiles and compared to that, my grind was significantly better.
Those MKKs and AMVs eat all AIM-120s you send them.