I think that there has to be a middle ground. Aside from private property, I believe dangerous and potentially harmful objects like guns should be regulated in public places. Not too tightly to interfere with self-defense and not too loosely so that weekly massacres like in the US are possible.

If society agrees that there are public places where people can meet, exchange ideas and express their opinions freely and without restrictions, these must be anchored in law and controlled by the state.

This also applies to the carrying of weapons. In the wrong hands, they can be used for anything from intimidation to murder. In the right hands, they can be used for self-protection and the protection of others. In order to be able to protect oneself and others, however, one must be able to operate the weapons properly, be familiar with various dangerous situations and be in a healthy, sane mental and physical condition.

That one fulfills these prerequisites can be confirmed simply by a certificate or a license, as it is with driving and many other things already the case. Similarly one should in my opinion also have to take a theory and practice examination in order to be albe to carry a gun in public sapces, in similar degree of difficulty as it is already for example with accquiring a drivers license. It is of course a restriction, but one that can be mastered by the general population. This way, it is easy to check whether the person carrying the weapon has a license to carry it in public areas and to take the appropriate measures.

With regard to the sale of weapons, this is certainly a more complicated matter. Because on private property, the state has only a very limited/no competence everyone is basically free to do whatever they want. But since weapons are sepcifically dangerous, I think they should be put into a different category of property than other items. Like the possession of nuclear, chemical or biologically dangerous substances or objects, certain weapons (such as firearms) can pose a particular threat to the freedom of others even when being only stored or used on your private property.

I am also of the opinion that such objects which present a special threat to the public (how this is finally defined is now negligible in this context and must be defined later. Conceivable would be criteria such as danger to freedom of life and body, controlability, impact area and duration, etc.) should be publicly registered. This could be approached with the help of a kind of pseudonymous public ledger, in which every purchase or transfer must be registered and then stored under a certain number. The place, date and type of item would then be registered and made publicly visible to all, so that everyone can see how many of these items are in circulation.

If there is a crime, all transactions of items corresponding to the evidence of the crime can be highlighted and a request can be made by the authorities to automatically assign these numbers to the persons having carried out said transactions and identify them. The numbers cannot be used to identify a person directly, but they can be decrypted one time per request and issuer by an open algorithm and assigned to a specific person without being able to link this person to other transactions or allow any other conclusions to be drawn about this person.

Conversely, gun owners can also verify that the gun they are carrying is legally acquired without disclosing other transactions or being identified again in the future by this number. These requests are of course also publicly documented and must always be justified by the requesting authorities. Of course, other control mechanisms can be added to the allocation of these requests if desired.

All in all, things that pose an extraordinary threat to the general public could be better controlled without creating major obstacles for the acquirers and thus inhibiting widespread adoption.