Your comment implies that there are two classes of people, "gun owners who understand firearms" and "non-gun owners who do not understand firearms". A casual glance at the deplorable accidental and unintentional discharge rates in the US statistics should make it immediately clear that gun ownership and understanding firearms have absolutely nothing to do with each other.
I say this as a non-gun-owner who was taught to shoot the old fashion way, by a 12 year old friend who got a rifle for Christmas when I was 11, and have subsequently taken enough firearms training, including in the armed forces, to understand firearms well enough to be terrified of the huge number of ignorant clowns who own them, no matter how well-informed and responsible the majority of gun owners are most of the time.
It is also worth pointing out that since the point of firearms is to make it really easy to kill things it would be disingenuous and stupid to claim anything other than "a gun owner only needs to fail in their understanding or self control for a moment to kill someone", and anyone who believes of their fellow gun-owners, "we never make mistakes"... well, people like that have good company in murderous tyrants the world over.
Everyone makes mistakes now and then. When people with guns make mistakes, other people die. Because the purpose of guns is to make killing really easy, and when you have a technology that makes something really easy you get more of it. To claim otherwise is to claim that intercontinental travel was as common before steamships as after, which is false.
Guns are a tool to solve a problem: killing things. Gun advocates in the US claim that this tool, and this tool alone, can be applied to the unrelated problem of personal safety. I say this is an unrelated problem because it is: in every other developed nation it has been solved more effectively than it has been solved in the US, without substantial reference to guns.
Let me say this again: the problem of personal safety has been solved better (people are safer) in every other developed nation without ubiquitous firearms. This is just a fact. Murder rates in Canada are lower than in the US. Murder rates in England, Australia, New Zealand, France, Germany, Switzerland (where firearms are all inaccessible, remember), etc are all lower than in the US. People in those countries are safer than in the US, despite the freedom of all Americans to carry firearms and the overwhelming victory of the gun lobby in the US in the past couple of decades.
So anyone who advocates firearms as a good solution to the problem of personal safety is like someone advocating bloodletting for personal health. It is a solution that has been tried and failed. It's time to move on to something else, like civilization and the rule of law.