What prompted someone to design this? I can't imagine a scenario where I would need the ability to have 13 rounds at the ready in the snow. Am I a Swiss military skier? After 2 or 3 shots, any living target is either dead or gone. Both circumstances don't require 10 more rounds for back up. In the snow you are already going to be heavily dressed so the additional weight of the loaded gun seems a burden, not to mention that most winter clothes have pockets where additional shells would fit.

Maybe if I lived in a polar region and I was only allowed one implement, then it makes sense. It could be a crutch, a club, a vaulting pole, and a spud to blow a hole in the ice for fishing. No fishing pole required, just shoot the fish.