Slow your roll Mr. Mitty. You blew your cred with the wrist rocket can take a deer larp. I use them daily to run off racoons with heavy ball bearings. Does it kill them? No…that's why I use it instead of a suppressed .22. Which, is what you should reinsert in your bb gun fantasies. That with the right ammo and well placed shots is just as quiet, maybe more so, and WAY more lethal. WAY more. Take it from a 25 year park ranger. When something needs to go nappy time without disturbing the patrons who are right there…a suppressed .22 with effective subsonic ammo is Darwin's Little Helper.
Experience trumps imagination. School's out. Speaking strictly for pest control, to be clear.
Also, to poke anothing tiny hole in your larp fantasy…if you shoot a man in the knee with your pellet gun, you aren't going to slit his throat. Your brains will be getting licked up by the dog his concealed 9mm startled when he shot you in the face.
Run around in the real world for a bit before you start giving ideas to others equally clueless.