Beautiful words. They do not make sense. Not sure if you served in the army and have basic concepts about weapons. I'll start with commonplace examples. Buy a live Christmas goose. Can you chop off his head yourself? Buy a live rabbit. I can tell you the technique of killing a rabbit. Can you do it?
Perhaps you do not understand, but there is a psychological barrier. It is extremely difficult to shoot a living person. Especially at close range when looking into his eyes. Some people cannot do this even to protect their own lives.
Now about the technique of owning weapons.
When a person carries a weapon he feels invulnerable, such a feeling is deceiving and at a critical moment he is often unable to use it. For example, a lady can start to panic and look for a gun in a handbag for a long time. Usually when he gets it, this will be a gift for the criminal. The gunman will pick up for himself.
Personally, I carry the melee weapons of the 8th century. I can give a name, but I'm not sure that it is known in the Western world. It is impossible to ban! It consists of a strong lace and keys. There have already been times when I had to use it. This weapon is ideal for close combat. But it is useless when a person is not ready to use it or does not know how to own it.
Believe me, for self-defense you need a simple weapon, even a primitive one. However, it is not a weapon, but the ability to wield it and readiness to use it.
There was a case when I came up against a pistol with my weapon of the 8th century. The criminal was not ready to shoot at a person, as a result, he presented me with a gun. It's not a firearm, but skills and willingness to apply.