It may depend on where you are. In the state where I live, there is no restriction.
No, it is not legal to buy a handgun at the age of 18. The minimum age to purchase a handgun in the United States is 21.
No, it is not legal to purchase a handgun at the age of 18 in Virginia. The minimum age to purchase a handgun in Virginia is 21.
the state of Missouri does not require handgun registration.
18
18 for a shotgun/hunting rifle, and 21 for a handgun.
Generally it is 21.
21
No.
It depends on where you are. In the U.S. 11 year old children cannot own a handgun, but it is legal under federal and most states' laws to possess the handgun for legal purposes such as hunting and target shooting.
It depends on what you mean. If you legally possess the handgun, then it is legal to have it in Tennessee. Tennessee doesn't require any kind of registration, however, you do have to have a valid handgun carry permit to legally carry it on your person or have it accessible in your vehicle.
All countries - once you have legal permission, allow you to carry a handgun.
In US law, there is no legal minimum for a handgun barrel- I have a Sedgely Baby Hammerless .22 Revolver with a 1 inch barrel. There IS a legal minimum (16") for rifles and shotguns (18")