Laws change place to place. Without knowing where you are, there is no way to answer. Sorry-
Have it examined by a good gunsmith
No. Very popular caliber since 1899.
Hand gun - 21; long gun - 18
At a minium, 21 for a hand gun and 18 for a long gun.
21 for hand gun 18 for long gun
21
21
21
If you have a gun permit, yes, as long as you are somewhere where it is otherwise legal to have the gun.
check with your state police
18 for long gun, 21 for hand gun
18 or 21 depending on if you are buying long gun or hand gun ammunition