Front bands

This may be a stupid question, but does anybody know why the front band on rifles is called the "top" band? What is it that makes the front of a rifle the top? In all my years, I don't recall ever hearing or using the term, but lately it seems to be the most-used nomenclature, but to me "front" makes more sense. I don't get it.

Spoken of as they sit in a rack. Left and right is spoken of as you hold the rifle to fire.

Thanks. In a strange way, it even makes sense! I thought it must be something along those lines, as when standing at parade rest with the butt on the ground, the muzzle end would be up. But still- front is front!