The way they NEVER shoot and only have like, 3 bullets. Sometimes they'll load one, crack the pistol back open, pull the same shell out and then load it in the next one they're showing off makes me believe they really don't waste ammo up there.
But the thing is, these pistols aren't like, luty level contraptions. They're nice. Like, rifled barrel, gun steel (at least on appearance), actual front and back sights, wood grips and....well, given how small they are, you can't really call it a foregrip. They look professional, like I'd buy one if I can find it. They sort of remind me of these.
Just shrink them down, immensely. To the point where I don't think any of the rifling in the barrel would matter for such a long cartridge.