As a legal hunting rifle 4 shots is all you need.
This must really get the gun grabbers in a twist, it doesn’t fire bullets, the design can be duplicated to some extant by a person with modest machine shop skills, all that is really needed is a high pressure compressor, tanks and the right material to use in a bullet mold.
I meant to say it doesn’t use a cartridge with gunpowder and a primer. It still shoots a projectile, probably the best way to describe it.
No. It propels bullets using air pressure.