alt Hacker NewsGuns are already ~20-50% efficient at turning chemical energy into kinetic energy. If you're not using a direct chemical reaction for energy, then you're using a human which is a lot less energy-dense than a backpack full of ammo.
And yes, people who do avalanche control typically fire explosives out of a cannon or drop them from a helicopter. Getting a machine supply all the energy is the whole idea instead of climbing mountains yourself.
Do you not understand the immense amount of energy and resources required to manufacture a single consumable cartridge?
The point is to avoid that entirely and harvest gravity.
Re-wilding teams already climb far and wide, and this would extend their reach without increasing their dependencies.
Ammo is a dependency.