The Colt M4A1 is a battle rifle. It appeared in the Season 10 episodes, Recovery (episode), Shell Shock Part 2 (episode) and during the Season 10 episode, Revenge (episode), NCIS Special Agents Leroy Jethro Gibbs and Timothy McGee are seen holding the rifles as they prepare to conduct a raid on a hideout. It is seen again in the Season 10 episode, Seek (episode). It appeared in the Season 11 premiere episode, Whiskey Tango Foxtrot (episode) and also the Season 11 episode, Past, Present, and Future (episode).