The shelf, or ledge shaping around the bottom metal allows for a transition from the width of the metal to a slim forend. I use a similar style with single shot for ends.
It is quite tricky to achieve the smooth transition on the sides of the stock as this one shows.
(That may be completely obvious to everyone??)
An interesting style with a very steep and sharp comb nose. Any idea what the peg in the for end tip is about?