I like your innovative thinking.

Here are my thoughts:

Hunting with a modern well constructed slingshot is challenging. Using an improvised device will be even more challenging.

The folding action of the handles might be a problem as the band is stretched and pulled slightly off perpendicular for a full stretch. Some experimentation with technique is in order.

The 'V' isn't far enough from your hand to keep it safe from getting injured upon firing. Again, technique may need some adjustment...

Looks like it's time for testing and video.