Agreed! However there is a psychological maturity that is gained when holding a loaded gun for the first time. It is quite sobering. What I mean to say is that people become more mentally sound when given greater responsibility.
Think of the changes that come over a man when he becomes a father.
Well to tell you the truth, I've never had a loaded gun in my hands, so I don't know the feeling you mean.
My opinion about children is only personal, and from the point of view of a city dweller, there are environments in which I think it might be justified, there are many environments where children are forced, in the good sense of the word, to mature faster, and it is possible that for them it is necessary to use weapons, such as tools to provide a livelihood for example.
But in reality I do not criticize those who give this type of experiences to a child, as long as, as you mention in your publication, it is done with all the responsibility and security of the case, always as an enriching experience and above all as a lesson about the security measures that should be taken with them and the risks involved in their use.
Now that in your particular case I see that your son is a boy of fourteen years, which in reality, puts him at an age where he should have the maturity consistent with the experience.