That's a cute analogy, so let's run with it.

For starters, I would posit that the U.S. occupying force in (take your pick of countries we've unsuccessfully invaded recently) is nowhere near an adequate simulation of the amount of force we'd utilize domestically if control of the government itself were threatened. In stark contrast to the relatively small number of forces deployed in each of Afghanistan and Iraq, every military asset under our control would be made available immediately to quell the domestic unrest, and upon seeing this mass insurrection, tens of thousands (if not hundreds of thousands) of able-bodied men and women would join up with the side currently in power -- for short, let's call them "The Union." Maybe some of the insurgents (we'll call them "The Confederacy") would be members of the military already, and would be able to abscond with a few humvees or a tank or two, but I don't think that would happen on any large scale.

I can't really game out a hypothetical play-by-play of such a civil war in the U.S. without knowing more about what supposed tyranny led to the uprising, as the duration of such a conflict, and the number of casualties, etc. would be related to how passionately the insurgents believe in their cause, but for them to believe in it strong enough to hold out against such overwhelming force, there would have to be some *serious* tyranny going on. Certainly more than just taking away certain classes of guns, forcing people to get an education in a government-run high school, or a 3% increase in the marginal tax rate on households with income over $250,000.

Then there's the issue of how exactly the Iraqi and Afghan insurgents have kept the U.S. (mostly) at bay. Sure, some of them are packing Kalashnikovs, but most of the "coalition" fatalities have resulted from improvised explosive devices. In other words, they don't really need the guns.

As an example of what the populace can do to end tyranny without firearms, I give you the Arab Spring. Imagine if Egyptian protestors, instead of peacefully assembling and bonding with the military, had decided to start shooting soldiers.

So, I think you've actually proved my point, which is that unfettered access to firearms isn't going to do a lick of good to help Citizens Joe and Jane fight against GIs Joe and Jane.