As long as they have procured it in a legal manner, and have all the requisite licenses and training, there is no reason to prevent citizens from owning weapons. To do otherwise is to prevent citizens from protecting themselves. What happened during Prohibition? Alcohol didn't magically disappear, after all. The same thing happens with guns.
While the second amendment protects the right to bear arms, at that time the guns were not nearly as powerful, fast, or deadly. There is no logical reason why a law abiding citizen needs to own an assault rifle in our society. The explosion of gun ownership in this country is going to bite us in the rear once these guns find their way into the wrong hands.
The right to constitutionally bear arms reflected the state of affairs in the U.S. at the time of its creation. It was solely intended to allow revolutionaries to defend themselves against British efforts to retain America as a colony.
This is not a complicated concept. Gun proponents, however, have distorted this original intention beyond recognition.
Their motivations are simple. Billions of dollars of profit from the sale of guns is at risk. No amount of window dressing or constitutional hand wringing can disguise this elemental truth.
The Constitution is pretty clear, Americans have a right to keep and bear arms, but it is not restricted to what kind of rights they have. I do not think the founding fathers ever predicted the culture that we have been in but none the less there is no clearer indication of the rights of citizens then the first amendment.
You can't have grenades, flame throwers, nukes or tanks. You can have automatic firearms and high capacity magazines if you are responsible, mentally stable and law abiding. We are allowed to own guns to defend our selves from tyranny and oppression as well as other things like rape and Burglary.