Section 38 defines a "realistic imitation firearm" as "an imitation firearm which has an appearance that is so realistic as to make it indistinguishable, for all practical purposes, from a real firearm". As a result of "real firearm" (defined in s38(7)) imitations of pre-1870 firearms are not caught by the new offence.
Whether an imitation firearm falls within the definition of a realistic imitation firearm should be judged from the perspective of how it looks at the point of manufacture, import or sale and not how it might be appear if it were being misused. Section 38(3) provides that in determining whether an imitation firearm is distinguisable from a real firearm, its size, shape and principal colour must be taken into account.