No one, that includes the States, the feds, the NRA; I mean no one. No one knows for sure how many guns there are in this country.
Even without armed revolt, it is a physical impossibility to take away every gun. It is just not possible to find them all.
Even if they think they have confiscated every gun imaginable, gun violence will still continue because it is a criminal matter, not a gun related matter.
Criminals are the violent ones, not the guns.
The lefties themselves, that includes the Uniparty, cannot see this because they are criminals themselves which is exactly why they have no problem skirting the 2nd Amendment, border laws, or whatever.
The left's issue is not criminal use of weapons. They have engineered a bureaucratic takeover of the United States with the invaluable assistance of the judicial branch and the legislative branch. That seething mass of goobers out there is not under their total control. They will have control.
I expect they'll overplay their hand.