I still dont understand why the shermans round is falling so short?
It's actually not falling short.
It's the gunsight, they are not relfecting sights. The "validity" (sorry, my english fails here) of the range marks is depending on having exactly a specific distance from your virtual head to the sight.
For example, go into a panzer and shoot at a target 800yds away. Now aim again, and then start to move your head forward - you will notice the range maks moving, all while your actual aim doesn't change at all.
I'm not sure if I have made my point clear now

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