I've honestly never understood the point of this. It's not *really* 1E6 rounds per minute, or 60K or 30K, or 300 - it's more like 36 rounds per minute, and that's being generous, since you'd probably need to be superman if you want to reload that thing in less than a minute.
So at the end of the day, what's the point of this? I can't imagine any practical use for this sort of device. I suppose it'll have some useful spinoff - if anyone knows what it is - please let me know.