A story like we've seen all to often before, but still impressive:
A drug house got knocked over by a gang of criminals dressed as police officers (helmets, body armor, the works) who ended up killing one man by fireing over 100 rounds of ammonution.
I'd be very interested in finding out what kind of guns were used here. This article mentions handguns, in this video, we can see a handgun holster recovered at the scene being bagged. I somehow doubt we're talking long guns that look like assault weapons, but a lot of articles mention "several weapons" without going into detail.
Still, even at 10 round per magazine, the six men would all just have to reload once to get these results.