I think it's incredibly unlikely Verm. It brings up several questions/points for me.
1. How do you end up in the type of situation where someone is going to "kick your door in with an AR-15"? Living in the ghetto? Selling drugs? Has this happened to anyone you know that was living a legit life?
2. If we had that type of collapse don't you think there would be A LOT of precursors that would give you enough of a heads up to either leave the country or then obtain the weapons? Do you see any hints of this currently?
3. Why are my insults the only ones you're identifying?
4. Is it sensible to fire an assault rifle in a close quarter home invasion setting, or would you run the risk of killing a family member or neighbor? I'm not in the military - but aren't shotguns and small firearms superior choices for that situation?