One thing that's quite apparent in this thread, is that some people are against there being rules or regulations, in the sense that they should be allowed access to anything they want, in some cases where the only reason may simply be 'for fun' or 'because I want it'. Just because a minority might misbehave and cause disaster, that shouldn't affect the majority who ultimately behave - I understand that view.
However.
You have to draw the line somewhere, not because we should sacrifice our rights and become slaves to a tyrannical government, but because you simply have to draw the line, if you want a sensible, civilised society where it's citizens can afford a reasonable level of protection and safety. If you don't or can't draw the line somewhere, you essentially open up the ability for people to have what they want, which may make people feel free or liberated somehow, but would the ability to own or do anything you like with no sensible rules - really translate into a better or reasonable society worth living in?
People posting in here, who support the idea that civilians should have general access to weapons which are derived from things used on a battlefield, probably haven't thought about how it would feel, if some of their loved ones were wiped out in a school shooting such as Newton or Parkland, via an attacker using such a thing. A bereaved individual in such a situation, would be well within their rights to look towards their leaders (the government) and ask "What can we do to prevent this" then expect their leaders to come up with sensible rules and legislation that attempt to prevent a reoccurrence, because that's what leaders are there to do, that's why we elect them, that's why we have laws and rules that we enforce.
Where would a reasonable person expect their leaders to focus their energy? Mental health, social equality, education, would all be prime candidates for attention, however I get the impression that some people on here, would expect their leaders to look at these issues - yet somehow turn a blind eye to the fact that it might be just a little excessive, to allow weapons of war (or close enough to be) into the hands of civilians.
They often make the point that "guns don't kill, people kill" to attempt to advance an argument that banning or imposing further controls on something won't make any difference, because nothing other than the person is to blame, however I think that ignores how people really behave.
In the wake of Sandy Hook, Dr Rowan Williams (then Archbishop of Canterbury) spoke on thought for the day back in 2012, and I think what he said stayed with me for a very long time, because for me it crystallised the whole issue and allowed me to understand it much more deeply. I'd urge anyone who wants to sit behind the 'guns don't kill, people kill' argument, to at least give 3 minutes to what he says on it.
https://www.bbc.co.uk/sounds/play/p0138b5h