Pressure Tank Gun

[Kovirii]

Emergency oxygen tanks don't hold that much gas in them, so you'd need to be refilling it often.

The thing doesn't shoot bullets. It shoots pens/shrapnel/potatoes/coins/paper/etc.

Yeah, making it use up a lot of gas would be sufficient balancing.

But could it shoot spent/unspent bullets, even if they don't act the same as bullets fired from a gun?