Everything will run out!!!
It is just a simple fact. No more shaving cream, no more toilette paper, no more tampons, and worst of all, no more bullets.
It might be a few years, but eventually all the bullets will be lost. That’s when a weapon like this will come into play, and I’d suggest practicing with one long before you need it.
It has a couple very practical advantages as well. its quiet, and you can use river stones of the right size and spherocity if you choose them carefully.
Range might be an issue, but I think Jorge can make it an even stronger ball shooter…