I've never understood this view. Even with this recent school shooting a trained deputy refused to go into the school and confront the killer. I just don't think in a panic situation someone will handle being shot at by assault rifle by calmly drawing a gun and shooting accurately back. Also with the 2017 Las Vegas shooting the shooter used a bump stock and rifle to shoot from a distance and no one knew where from so no chance to defend yourself. If you take guns both legally and illegally owned out of the system like we have in the UK you just don't have to worry about being shot at. Also what good does a gun do against a bomb?