Regardless of your stance on guns, the "protect from tyrannical government" mantra is a load of crap. All decisions are made by elected officials. Those decisions are also subject to review by the court system.
We don't live under a dictator. Our government consists entirely of normal people, who may have a shot at some influence for at the most 8 years. There are 535 members sitting in Congress, and the majority of them must agree on "Hey, let's get the military to kill our citizens." Funny thing is, most of them will be citizens after a few years. Then they who made that decision will be subject to the horrific laws they set forth. And how do they decide will and won't be eligible to get shot? I'm sure most of Congress has your average family of citizens sitting at home.
The United States government will not and cannot "get you". It just doesn't work that way. We are a government of the people, by the people, and for the people. But one way it will certainly perish from the earth is giving millions of uneducated, drunk, and spiteful hillbillies assault rifles.