I've always heard that it was called a "Hunting Sporran" because it had less moving parts to make noise. But then again, that sounds like a major assumption that made it's way into popular opinion. I like the way Hunting Sporrans look, and as far as crafting, they are one of the easier styles of sporran that a fledgeling sporran maker like myself can put together.

Picture (courtesy of KiltMart) for everyone confused about the style "Hunting Sporran", but generally it's a flat, open-topped sporran, traditionally with a leather cantle, and tacked-down ribbon tassels built into the face...