Firing a German Pak-40 75mm Anti Tank Gun

[fwayner]

I am tempted to believe that the tiny gun shield is there to protect the small pieces of the gun: "We can always get more crew".
Alternatively: "this shield will be of some assistance as long as the barrel is pointing directly (I said Directly) at the enemy."
Either way, clearly a design feature designed by designers not planning on doing the firing.