I have noticed that since Donald Trump even suggested putting gun control on the table as a possibility, the second amendment people have flipped out.
My question is this: If the US government made it more difficult to buy semi-automatic rifles, would that really make it any more difficult to rise up against a tyrannical US government? Let's be real here - if they're coming for your guns, they're not sending in the local Sheriff to get shot. It's the most powerful military on earth coming to your suburb with everything at its disposal (tanks, jets and nuclear weapons).
You've probably already lost the ability to rise up against tyranny. Even if you haven't, a militia of 10-20 million shotgun, pistol and single shot action rifle toting men descending on Washington isn't going to be much less effective than if those same people had semi-automatic rifles.
That third paragraph is something gun rights advocates don't really consider when saying the 2nd amendment is needed as a check against governments. As a Brit, I feel safer knowing that the odds of me coming across a guy with a gun are very slim, compared to being in American where any nutter I look at the wrong way may take up the issue with his pistol.
As for the self-defence argument, I think you could reasonably say a pistol is for self-defence, maybe a shotgun if it's kept at your home, but assault rifles and semi automatics are weapons of war not defensive tools.
The US will not change it though. The NRA will not allow you to have a grown-up debate about it. Stopping even legislation that restricts the mentally ill getting access to gun is just plain insane. Also, the US has so many guns that to reduce the scale of the problem you probably would need to take away at least some of them - and clearly that wouldn't go down well.