Gun restrictions don't seem all that different in principle to driving restrictions. Granted, driving restrictions are partially justified on the grounds that you're using public roads, but the main point is control of an otherwise overly dangerous contraption. Getting a driver's licence in the US is quite easy, it seems, compared to how stringent it is in Australia, but I'm sure making the requirements stricter would not meet nearly the same opposition as what is termed 'gun-grabbing'. Yet even though the two types of restrictions as comparable, they cannot be equivalent. The legitimate purpose of driving a car far outweighs the risk posed to others. That is not to say that there is no risk, or that in some cases there is unacceptable risk. It's just that the risk is justifiable on the grounds that there is far greater utility in allowing reduced restrictions on driving (as compared to guns). On the other hand, guns do not have nearly the same legitimate value (however legitimate a purpose or purposes you may think they have, surely no-one would contend there isn't far greater utility in society's most widely-used means of transport), and the risk they pose is relatively significant. This basic realisation in itself indicates that obvious point that there should be more restrictions on guns than on driving, and from there it's just a matter of how great you consider their legitimate purpose as compared to the damage they can do. I don't believe there is any legitimate reason to own an assault rifle, for instance, so it's natural to conclude that you shouldn't be able to personally own one. In an urban environment, there isn't really any legitimate reason to be carrying or using
any sort of gun; the number of situations in which you might have a legitimate reason to use a gun are so negligible that they shouldn't have a drastic impact on policy. Being mugged doesn't provide a legitimate reason, because any use of a gun would be disproportionate to the potential loss of property.
I would not have thought that a Constitution would be incapable of changing to cope with clearly different circumstances to that envisaged. However, stranger things than the US Constitution being ridiculous have been known to happen, so it's not like I couldn't be persuaded that the US Constitution does rightfully prohibit gun control. But if you're taking that view, the 'shall not be infringed' part is pretty clear and the rationalisation for some gun restrictions would seem to be the same as the rationalisation for all gun restrictions.
What is the 'general right to self-defence'? Surely it does not involve anything beyond a proportionate response. If you accept that restricting the ownership of RPGs doesn't infringe on this supposed right, then you accept that restricting other types of weapons is simply a matter of balancing the legitimate purpose against the risks.
Just because you have to have a licence to drive a car doesn't mean your innocence has been brought into question in the absence of proof of guilt. It would be silly if everyone was allowed to drive as they pleased up until the point where they caused some sort of accident, simply because up until that point they'd done nothing to demonstrate their inability to drive, or there 'innocence'. Society deems it appropriate to proactively minimise risk rather than sit back and wait for the consequences and deal out punishment accordingly. This is the same concept as with duties of care; you owe one whether or not you've done actually done anything wrong.
Alcohol can cause societal harm, and this is why there are some restrictions on it (e.g. tying into the driving example, drink driving). But going back to legitimate purpose, alcohol actually has much more of one, and the risks to others are not as great (a large part of the risk is to yourself). It's simply a matter again of weighing the risks against the benefits.
If the same number of people, that were killed with firearms, were killed with butter knives, would it be any less of a problem? The issue is violence itself.
This would seem to be missing the fairly obvious point that butter knives in fact
aren't killing the same number of people.