You can fire a shit-ton of bullets in an instant, but since the barrels are the magazines the ammunition supply is very limited and there is no practical way to reload it.
I'm also pretty skeptical of the accuracy because the bullets would have varying barrel lengths.
I got curious and looked, sounds like the company that made this spent almost 20 years hyping this technology while being unable to actually get anyone to buy it. They were put in voluntary administration in 2012, delisted in 2013, and went tits up in summer of 2014.