Little bitty rounds mean low recoil... And I'm guessing that if Abduhl gets hit with 20-30 of those "angry little bees," that he won't be thinking about payback, while at the same time, if he gets a through-hit from a FMJ, he could still be somewhat viable as a threat.
I've shot a 180 before, and it's basically a one-barrel bullet hose... Wrap six rotating .22LR barrels in a sleeve, stick a thousand-round box on the back, and you've got a higher cyclic rate... And the .22LR could be somewhat climate-proofed too...
And since it's a mechanical feed/fire/extract system, if it hits a dud, you're still good.
Besides, if someone makes it, there's the chance that dealers samples could be available, and then I would have the chance of owning a minigun that I could afford to feed...