I'll start off by saying that the idea of having to fight the government in the US is, at least for now, an incredibly unlikely situation and I think everyone who argues in good faith knows that. That said, those "boomsticks" kill a man the same as any other gun. I know what many will think "how are you gonna take on an Abrams or F-22 with your AR-15?". Here's the rub, you really don't have to fight those. A tank and stealth fighter don't patrol a neighborhood. Infantry do, and they die to bullets just like the rest of us. A determined populace with primarily small arms can do incredible damage to an occupying force in men and morale. I'm skeptical a majority of US military personnel would even follow through with turning their rifles on their fellow citizens (hence this being an incredibly unlikely scenario), let alone be okay with the high civilian casualties that using much of their heavy weaponry would cause. Please revisit the US experiences in Vietnam, Iraq, and Afghanistan.

Also worth noting that the founding fathers' definition of "well regulated" is not the same as our modern usage. Take a look at the militia acts of 1792. Their "well regulated" was essentially ensuring every able bodied male had a musket (or rifle), bayonet, ammo and powder to go with it and knew where to report to if they were called into service. A far cry from what many gun control advocates would think of as well regulated.