“I can’t have anything unless I can prove I need it? Since when? So now is it the case that everything which isn’t provably necessary is instead forbidden?”
Steven Dan Beste notes the problem in the questions about Why does anyone need a high-capacity magazine for their pistol? Why does anybody need an AR-15? that comes up in the arguments about guns.
“I own lots of things that I don’t need. It’s called “Freedom”; I don’t have to ask permission from my betters to buy things, and I don’t have to offer justification for doing so. It’s nobody’s business but my own if I buy things I don’t need, as long as I don’t rob a bank to get the money I spend.”
It’s called “Freedom” – the question is really about just how much government should interfere with individual freedoms. You can see how that one is distorted from honest debate to useless argument with such things as ignoring unpleasant realities and the use of logical fallacies.
As for reason and logic, consider Mark Almonte’s answer to the question Why does anyone need a high-capacity magazine?
“There are several reasons for civilians to own high-capacity magazines: the right to possess the necessary means to effectively defend themselves, misconception of bullet stopping power and shooting accuracy, and the issue of multiple attackers. Additionally, on a net balance, there are benefits to the community when law-abiding citizens own guns with high-capacity magazines.”
When you are dealing with people who feel that members of a civilized society should have no need for personal defense – else it’s uncivil or perhaps because the police will do that job – then there is no basis for trying to discuss the idea of responsibility for personal defense.
The reality of a shooting situation is why the fantasies of one shot, one kill, immediate stop with any personal weapon are not helpful. It is why the AR-15 is gaining over the shotgun as a home defense weapon. Any weapon will require proper training, a good aim, and, more than likely, multiple hits to achieve the desired effect. But that is reality, not the fantasies that often drive the argument.
Related to this, see Colorado Fights Concealed Carry on Campus: Why, Exactly?