It could be argued that The Constitution is a solid reason for gun ownership, 'the right to keep and bear arms'. I will not dispute that one bit. The ability to defend oneself in a 'dangerous' world is an important aspect of living and staying alive. Where the problem lies is when the 'right' is taken as allowing someone to own an assault rifle with a significant number of bullets in the magazine and other forms of weaponry with a killing power beyond the ability to defend. At what point should a limit be imposed (if at all)? Tanks? The nuclear bomb is an 'arm' for defense and there are several laws prohibiting their ownership and use due to the significant harm it could cause. Why then not a specific limitation on a weapon for 'personal defence'?
With the above in mind, it is worth noting that the 'right' appears solid when taken out of context. However, the words "a well regulated militia being necessary for the security of a free State", and the words "common defense" clearly show the true intent and meaning. And there is one of the major issues regarding the 'right'.
About 47% of the US population declared they owned a gun. A simple question. While people defend their right, why did NOBODY in the audience at the Dark Knight movie use one of their weapons to defend themselves? There are some 2 million uses of a weapon used in defence in the US each year.
This map here shows there is a multiple victim shooting in the USA every 5.9 days. It is important to note that there are about 4 million (known) assault weapons in the US and this type of weapon represents about 0.20 of 1% of all shooting incidents. Rather than getting in an outrage about the type of weapon used, it is far better to implement an 'are you suitable for owning a gun'. Look at the requirements in the top graphic and think on it...