(I wrote this in response to a FB status which I considered to be thoughtful and inviting of discussion)
Well... I think Chris Rock has a point, but I don't think you can make bullets cost $5k without abridging someone's rights. I think we can all agree that no one has a right to "take down" anyone else. The point of a "right" is that you are free to do something without the interference of government/law-enforcement-officials.
(FYI - I own a gun and I am quite responsible about it: it stays locked away for periods of extreme lawlessness, or for practice against paper targets.)
The problem with preventing rights violations (such as murder) is that a person has to be mortally victimized in order for the perpetrator to have demonstrably violated another's right to life. But it is proper that the law should have to prove its case against a criminal. It is a worthy cause to ensure that our governments cannot arbitrarily revoke someone's rights. Tyranny and systematic imprisonment of political enemies is the inevitable result of a failure to do so.
Regulations are tricky and have unintended consequences. For instance, bans of items have proven to create black markets and empower aggressive organized criminals (e.g. prohibition of alcohol and drugs), which causes a different ripple effect of murder. And regulation can also be used tyrannically against political enemies.
My desire to have a tyranny-minimal government means, unfortunately, I have to wait for a killer to show that he is indeed a killer before I let my government throw the book at him. I don't know that it is possible to engineer all of the crime out of a society without engineering the liberty out of it too.
An easy way to get the silent assent of your detractors is by attempting to seize the moral high ground without their noticing. I see this tactic used all of the time in political discussions.
One of the things you learn from Objectivism is to identify and explicitly question moral premises of arguments that are presented to you. It is good inoculation against exhortations to honor "Social Contracts" you never made.