Large crowds get brave precisely because of their number. When confronted by someone with a firearm who clearly will use that firearm or actually discharges it, however, they generally RUN in the opposite direction. People riot because it is fun. The possibility of being shot reduces the level of fun dramatically.
All they can do is try to outflank you - and that is after they get a second wind of courage. The key is to keep moving after firing your weapon. Your movement - especially if you can move out of sight - helps to confuse the crowd. By the way, when shooting into the crowd shoot those closest to you, and then those who are largest. That teaches a simple lesson: Get near me you die...and...Just because you’re big doesn’t mean you can’t die.
"Guns are like parachutes. If you need one and don't have one
you'll probably never need one again."