[SlowBoat407]

The video at the site says there's no recoil. That must mean that mass leaves in at least two directions. If the recoil is very small then there is very little mass projected, the exit velocity is small, the weapon mass is great, or some combination of the above.

I'm not a physics whiz, but it seems all you'd need is something to absorb the counter-rotational reaction. A flywheel maybe?

[Born to Conserve]

A "black box", no matter what its internal workings, will have recoil if it is projecting mass. There is no way around this.

I think they must have meant "no recoil" in a loose human-perceptive sort of way.

[Old Dirty Bastiat]

Or another DREAD spinning the opposite direction?