Nothing contained in this chapter prohibits:
(1) an act of a law enforcement officer performed within his official capacity;
(2) training for law enforcement officers conducted by or for an agency or a political subdivision of a state or an agency of the United States;
(3) activities of the National Guard or of the armed forces of the United States; or
(4) classes intended to teach the safe handling of legal firearms for hunting, recreation, competition, or self-defense.