['88Scrat]

Ok I need someone to explain something to me. This could be perceived as a dumb question...

Why when I take my SMLE No.4 MK1 and shoot with the 300 yard battle sight zero at 50 yards am I hitting a foot or more ABOVE the target? In my head I imagine this as two lines intersecting at a 45° angle at 300 yards (yeah I know thats an exaggerated example) with the top line representing the sight picture and the bottom line representing the travel of the bullet. Move the target forward and the top line, representing the sight picture, doesn't change but the point of impact should now be in the dirt right? I know bullets fly in a parabolic arc but could it really be that pronounced?

Man, not knowing this makes me feel kinda stupid...