(1) In this Act:
"firearm"—
(a) means a gun, or other weapon, that is, or at any time was, capable of propelling a projectile by means of an explosive force, however caused; and
(b) includes—
(i) a blank fire firearm; and
(ii) an airgun; and
(iii) a paintball marker; and
(iv) something declared to be a firearm under section 31; and
(v) a modified item; and
(vi) a firearm frame or firearm receiver that does not form part of a firearm.
(2) However, "firearm" does not include—
(a) something prescribed by regulation not to be a firearm; or
(b) something declared not to be a firearm under section 31.
(3) In this section:
"modified item" means something that would be a firearm if—
(a) it did not have something missing from it, or a defect or obstruction; or
(b) something had not been added to it.