2nd Amendment of the United States "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
The second Amendment was intend to give, the Militia's of the United States, the power to bare arms as they were comprised of the average citizen. The second amendment doesn't protect guns; it protects arms. Arms can be a knife, a club, a rock, a sword, a gun, a rocket launcher, a tank, a nuke, etc...
If I we had an amendment that said, "Being 21, the age of adulthood, it is the right of the people to drink alcohol." Most people would say, you have the right to drink at 21. With the second amendment, most gun enthusiasts ignore the first part of the amendment and they ignore the fact that it doesn't say guns.
At the time, when the second amendment was crafted, the United States didn't have its own military. A "tyrannical government" was considered those outside the United States as we were fighting the British who were trying to control us. Seeing how, we the people of the United States, are the Government (as we use elected officials to represent our views); the ideology wasn't intended to attack ourselves. I won't comment further more on this topic. I support gun ownership. However, there are extremists an both ends.