No, Really, Regulate the Bullets

To reduce the likelihood of a totalitarian state. It was written by people who had recently participated in a violent secession from the world's largest empire. Self defense against ordinary criminals was another factor, and the Supreme Court has ruled that individuals have the right to own weapons for that purpose.

I can see the purpose of the "Free Speech" it makes sense today more than ever.

Limitations on the right to free speech are active political issues today. There has recently been a major push to limit "blasphemous" speech in western Europe and the US, for example. Source code as speech when the code does something governments want to regulate, like cryptography or DRM circumvention is not an entirely settled question, to provide another example.

What if unpopular rights are those that kill children

I count at least six out of ten amendments in the Bill of Rights as likely to have led directly to children dying. Free speech has led to violent action. Availability of weapons makes violent people more deadly. Four more amendments protect the rights of those accused of crimes, some of whom are required to be released when they would otherwise have been jailed. Some of those have killed children after their release.

Rights that are just a little unpopular don't need so much protection. The important rights all have the potential to get people killed, as does the lack of them.

Ok but doesn't that imply that the founding fathers somehow foresaw the advent of nuclear arms, school shootings, the internet and created a concise set of laws that would prevent us from sneaking in laws by creating loopholes.

Of course not. That's why we have courts.

The courts try to apply the original intent of the Constitution to modern situations. The authors of the Fourth Amendment probably couldn't have imagined laser microphones, but the courts have held that using one (or anything else high-tech) to eavesdrop on conversations you have in a private place is just like a search and requires a warrant. In other cases, the courts have limited the application of rights to new, unforeseeable technologies. The Supreme Court ruled, for example, in DC v. Heller that the Second Amendment doesn't apply to unusual and dangerous weapons; it protects the right to own handguns, but not nuclear warheads.

It is, of course perfectly reasonable to have a discussion about whether a right protected by the Constitution has a place in a modern society or if it should be eliminated or changed. My original point in this discussion is that we should not want it to be trivial to bypass Constitutional rights, e.g. by banning ammunition instead of guns because it would then become trivial to bypass any of them, at any time, for any reason.

And, yes, addressing the gun culture will have to be a component of this. But violent cultures can be changed. The US is a past master at it -- look at the post-WWII reconstruction it orchestrated in Japan.