The police look impressive when they are bursting in on ONE house. If they have to take ten houses they have to draw on reinforcements from other cities and sometimes other states.
They simply do not have enough warm bodies to do a mass confiscation.
When you look at the numbers and then look at the territory they would have to cover and it becomes even more of a problem.
They MIGHT be able to do a mass confiscation in TWO major cities if they throw everything they have into the pot.
But who is going to be protecting them from the enraged citizens in the rest of the country when they find out what is happening? And it would get out. There is no way you could keep this kind of thing under wraps.
That, and the fact that they're vastly outnumbered by the gun owning public, and therein lies their quandary.
In short, the American people can't be disarmed by force. That can only be accomplished through a slow and steady degradation of our second amendment rights.
Unfortunately for the totalitarian left, CWII will happen before they get anywhere close to taking our guns.