This, like Daley bulldozing trenches into the runways of that Chicago airport is a limited event thats easy to pull of quickly using the element of surprise.
There are over 100 million gun owners distributed across the US. It would take weeks, even months, to launch surprise raids that would scoop up most weapons.
After the first night there’d be no element of surprise. Using this sort of tactic, any sort of tactic, to confiscate guns isn’t going to end well.