(1)This Part of this Act applies to all firearms as defined in section thirty-two of this Act, except the following weapons and component parts thereof and accessories thereto, namely—
(a)a smooth bore gun having a barrel not less than twenty inches in length;
(b)an air gun, air rifle or air pistol not being of a type declared by rules made by a Secretary of State under this Act to be specially dangerous.
(2)This Part of this Act applies to all ammunition as defined in section thirty-two of this Act, except the following articles, namely—
(a)cartridges containing five or more shot, none of which exceeds nine twenty-fifths of an inch in diameter;
(b)ammunition for an air gun or air rifle or air pistol;
(c)blank cartridges not exceeding one inch in diameter.
(3)For the purpose of this section the diameter of a cartridge shall be measured immediately in front of the rim or cannelure of the base of the cartridge.