Canada's PM just outlawed "military style assault guns". The key word is "style" because these guns are not automatic machine guns and would't be used by any country's military. The King of Canada has spoken, just what the American constitution protects against in the US. What is the legal basis of his edict? Off with their heads.
Alan, try to stick to your area of expertise, whatever that may be. Most US military rifles didn't have full auto, though that may be changing. They had a selector switch which the operator could move between single-shot and burst mode, with burst mode firing three rounds. Full auto, which was give to certain elite units, would allow you to dump an entire magazine. For soldiers with less training (and most have less training than the elites) full-auto would allow a panicked reaction that would leave the soldier with an empty magazine just when he needed it most. Most soldiers were told to keep the weapon on single-shot, which is essentially what a semi-auto does, EXCEPT that work-arounds were provided by certain American companies (called bump stocks.) Bump stocks essentially allowed semi-autos to be fired in bursts, and that made them into something close to military assault rifles, although bump stocks are inherently inaccurate and are useful only for shooting into unarmed crowds, as happened in Las Vegas.
These rifles basically have one function: to kill people. In many states, until recently, these .223 rifles were not allowed for hunting because they weren't deadly enough. The .223s are actually considerably less powerful than common bolt action hunting rifles, and weren't allowed because there was evidence that they created more wounded animals, which would get away and then die a slow death, than more powerful rifles. Further, these rifles are generally less accurate, and even when well-tuned, can't compete with a well-tuned bolt-action. If you want to punch paper and test your accuracy skill, you'd be better off with a bolt-action. If you want to hunt, you'd be better off with either a more powerful rifle (for big game) or a less powerful one (a .22) for small game. I've given up hunting, though I still have a hunting cabin in Wisconsin, and when you'd be out during deer season, and you'd hear a bap-bap-bap-bap-bap from a .223 or an AK, you'd think, "Oh, shit, some clueless asshole is out here in the woods with me."
The idea that these rifles could be used to fight off a tyranny in the US is a fantasy indulged by people who like to intimidate others with their weapons. If there is ever a real tyranny in the US, it will be supported by the military, who would eat these wanna-be patriots for lunch.