Five is not too young to learn the proper use of guns,but they should be out of reach except when they are supervised.
How about 4? Thats not too young, is it? Maybe even 3?
Three is not to young to shoot. I have plenty of pictures of my son shooting a gun at three. I am of course hands on the firearm at all times. In fact it is a cricket that he was shooting.
It really all depends on the level of supervision that someone plans to give. I have never had an issue with one of my children being curious about the guns. I have a 10yo daughter that shoots trap. She has also handled guns since she was very young.
Hmmm. three might be a little young to learn the mechanics, but it is not too young to start learning the safety parts of gun ownership... .