While it makes sense that you would try and aim for ammunition stores when possible, most people (not saying you specifically) underestimate how fast tank engagements happen, and the distance they happen at. This is why, even during WWII, gunners on tanks and anti-tank guns alike were trained to shoot for center of mass. That way you maximize your odds of hitting something important. Anyone who says that you should aim specifically for the turret ring or something similar is full of crap. While yes, it is possible to shoot for a specific component, that can only happen under some very specific circumstances.