Suggested by Flying Junior
The purpose of the 2nd Amendment in America was to ensure that state militias continued to have the power to tyrannize slaves, to suppress their rebellions with lethal force, and to suppress any other rebellions they felt went against their "rights" to tyrannize others.
It was put in place to do pretty much the opposite of what gun nuts claim today. It was put there to enable governmental suppression of slave rebellions, first and foremost -- not to protect the rights of those who wanted to rebel.
From this most interesting post on Che Pasa
Coyote kills (and wolf kills and mountain lion kills and buffalo hunts and so on) these days are said to be justified because of all the damage these animals cause to livestock and crops. "Everyone knows..." Except they don't. And the farmers and ranchers often wildly exaggerate their losses. The real point of these killings is not to protect livestock and crops, it is to assert life and death power over the Other, in this case, the Natural World.
Gun rightists don't care a whit about preventing "tyranny" in any rational sense. By and large they were either silent or actively cheering on the gutting of the rest of the Bill of Rights by Congress and the Executive during recent times, most being "patriots" and all who don't believe in such luxuries as "rights" when it comes to other citizens and terrorists -- who are often one and the same in their view. While a modern form of tyranny was being imposed and consolidated even before the advent of the Glorious Global (and Forever) War on Terror. In other words, throughout the abrogation of what remained of the Bill of Rights, Sacred Second believers either paid no attention (as long as no one tried to grab their guns!) or they were in the vanguard of the cheerleaders, where most of them still are.
They don't want to prevent tyranny, oh no. They just want to be sure they're the ones to impose it.