This would not probably happen for at least 8 - 10 years. Ad that to your current age to factor in how much urban combat you'll have left in you.
Sure, if we're only talking about one house. How would the government go about disarming a whole block? A whole neighborhood? A whole city? A whole state?
Its ludicrous to even contemplate. The manpower for such a thing does not exist.
Also consider - if the government were to target the entire population in that way, it would be seen by one and all as the ultimate act of treason, and would compel an overwhelming response of force by the citizens.
Yup, you get it...
I train heavily and if you arent moving in an urban (many other types too)firefight, your chances of becoming a casualty are greatly increased.
I guess a bunch of old fat guys could hole up and throw a lot of lead in a last stand, but that will be their first and last fire fight.
If you dont shoot and scoot in an urban environment when facing superior fire power, fire will be concentrated on you and you will die.