Well, the reality is (the one we're not suppose to talk about) is that the best strategy is to hide your firearms from confiscation, then later on engage in a guerilla war type resistance of ambushes, bombings, assassinations, kidnappings and whatever tactic can be used to combat the tyrannical regime.
It's the only way really. We condemn certain middle eastern guerilla forces today due in part to the way we see things and propaganda, but the reason they do the things they are doing is because they're up against a high-tech super-force. They have no other tactics or options. We'll be no different. We'll be worse off actually, as other guerillas around the world have more supplies, full-autos, RPG's, mortars and explosives all in a region that is underdeveloped and as a result - not a technological police-state. We have far less effective weaponry, and we live in a place that is far more controlled.
The men who founded this nation were considered dastardly and dispicable due to their unconventional and "cowardly" tactics. If the word "terrorist" existed in 1775, I'll give you guys all one guess who the British would label as that?
The truth is, there are NO rules in war. That is true of 4th Generation War. It's all war, just different forms of it. Violence is violence - and people will do whatever it takes to acheive their goals. It's all the same.
This assumes that people will react in this way to a massive gun-grabbing apocalypse. If they don't - it's over. The last chance for a society to combat tyranny is to draw the line at firearm confiscation. After that, the people have no more leverage, nor do they have the means to change anything. The tyrants will achieve a total monopoly of force - and everytime that's happened, there have been mass genocides.
Laws, words, movements, consitutions, bills, amendments are all meaningless without the ability to project force. There's a reason why authorities have firearms, because we want them to be able to enforce the law. The law is meaningless if there's no way to project force. Why? Because people will test authority by upping the ante - and the logical conclusion of that is bloodshed via lethal force. Likewise, tyrants will up the ante - but before they do - they want to make sure you can't shed their blood first. This is just the reality of the world.
Hopefully, we can let the PEN do the work instead of the sword. Dunno if I'd like to live through something like that.