You don't understand natural rights if you think they give you a right to own a weapon

 "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness."

I will admit I have a lot of problems with the concept of "natural rights" with the major one being that they don't exist. The reason I started this post with the quote from the Declaration of Independence is that is says "liberty" would be a natural right. As an extension, so would slavery, yet the person who wrote that owned slaves and raped one of them: Saslly Hemmings.

And if we are getting into that they are "god given", shouldn't they be somewhat in line with the ten commandments?  Establishing natural rights seems a rather straightforward thing to sort out amongst citizens, but even the most basic natural right, the right to life, is fraught with potential pitfalls such as 'does that right include or exclude the right to an abortion or the right to euthanasia?' But more in line with this is the ability to use deadly force despite the commandment "thou shalt not kill". 

As I point out for one of my arguments that the Heller decision is wrong is that the use of deadly force in common law at the time of the drafting of the constitution was a last resort. The common law scholar, Blackstone, wrote concerning this the law of self-defence:

THE defence of one’s self, or the mutual and reciprocal defence of such as stand in the relations of husband and wife, parent and child, master and servant. In these cases, if the party himself, or any of these his relations, be forcibly attacked in his person or property, it is lawful for him to repel force by force; and the breach of the peace, which happens, is chargeable upon him only who began the affrayd . For the law, in this case, respects the passions of the human mind; and (when external violence is offered to a man himself, or those to whom he bears a near connection) makes it lawful in him to do himself that immediate justice, to which he is prompted by nature, and which no prudential motives are strong enough to restrain. It considers that the future process of law is by no means an adequate remedy for injuries accompanied with force; since it is impossible to say, to what wanton lenghs of reapine or cruelty outrages of this sort might be carried, unless it were permitted a man immediately to oppose one violence with another. Self-defence therefore as it is justly called the primary law of nature, so it is not, neither can it be in fact, taken away be the law of society. In the English law particularly it is held an excuse for breaches of the peace, nay even for homicide itself: but care must be taken that the resistance does not exceed the bounds of mere defence and prevention; for then the defender would himself become an aggressor.

Blackstone’s Commentaries on the Laws of England, Book the Third, Chapter the First: Of the Redress of Private Wrongs by the Mere Act of Parties p.3

In the Enlightenment, some of the greatest minds in history set themselves the formidable task of thrashing out just what should be considered natural rights. In fact, there is quite a debate as to what exactly these rights would be and how they come about. I've already said that anyone can claim anything as a right, but whether your claimed right is accepted is another matter.

I would also add that this is a much more complex philosophical issue than most of the people who talk about it realise.  It's not the libertarian state of nature, but an acceptance of a social contract. And even the state of nature has its rules. And the rules come from the use of reason which makes everyone equal and by necessity must respect other's rights. Expecially in ways that would harm another in his life, health, liberty, or possessions.

The motivation behind the individual’s leaving the state of nature—the state of liberty—lies in the uncertainty and insecurity of enjoying life, liberty, and physical goods.  Locke recognized in his Second Treatise of Government  that individuals would perceive themselves in the following way: “For all being kings as he, every man his equal, and the greater part no strict observers of equity and justice, the enjoyment of the property he has in this state [of nature] is very unsafe, very unsecure.” Individuals, therefore, must remain in a state of vigilance against others who do not properly use their reason to recognize the truth of natural rights. Instead of living peacefully, acquiring property, and pursuing their own conception of happiness, individuals must stay vigilant against those who are willing to violate another’s life, liberty, or property, thus presenting a barrier for others from enjoying any or all of them. Hence, it is rational to consent to a social contract, even for those who would not follow the natural law in the state of nature, and establish a government that quells this state of “continual danger.” The end—or purpose and final cause—of “uniting into [a] commonwealth” and erecting a government, therefore, is “the preservation of property”—where property is understood to include life, liberty, and property.

Citizens relinquish some of their powers from the state of nature; more specifically, these include the powers of “doing whatsoever he [thinks] fit for the preservation of himself” and “punishing others” whom he thinks committed injustices against him. Locke believed that citizens should first establish general and promulgated law “received and allowed by common consent to be the standard of right and wrong, and the common measure to decide all controversies between them.”

The reality is that even if you want to claim a "natural right", there needs to be some consensus from society about that right. The problem with the Second Amendment is that there is so much misinformation about it out there and very little fact.  I found an interesting abstract on this which pretty much sums up what I am saying:

A growing body of scholarship claims that the Second Amendment was intended to enable individuals to exercise their natural right to self-defense against violence. In this Article, Heyman shows that this view is based on a misunderstanding of the natural rights tradition, as reflected in the works of Locke and Blackstone, the post-Revolutionary state declarations of rights, and the debates over the Constitution and the Bill of Rights. Natural rights theory held that, when individuals entered society, they largely gave up their right to use force against others in return for the protection that they received under the law. And while the people retained a right to resist and over- throw governmental tyranny, this was a right that belonged not to private individuals but to the community as a whole. In this way, Heyman argues, the natural rights tradition provides more support for a collective right than for an individual right interpretation of the Second Amendment.

Steven J. Heyman, Natural Rights and the Second Amendment, 76 Chi.-Kent L. Rev. 237 (2000).
Available at: https://scholarship.kentlaw.iit.edu/cklawreview/vol76/iss1/8

And if we are going down the path of it being a natural right, it has fallen victim to absurdity: not reason. The concept of natural rights does indeed mean that people have given up their "individual rights" to be members of society. And to claim that something which is detrimental to society is a "right" is absurd.