5.56mm round

The 5.56mm round is a type of ammunition in Fallout 3, Fallout: New Vegas, Fallout 4, Fallout 76, and Fallout Tactics. All weapons using 5.56mm rounds can use .223 rounds.

Background
 Originally developed for the M16 service rifle of the United States Army. It is a rimless, bottleneck cartridge that offers tremendous wounding potential under the right condition. Its performance and popularity among military forces endures despite the Great War: By 2287, it has served Americans for over two centuries, from the United States Army to the New California Republic Army.

5.56mm round
Ammunition. 5.56mm caliber.

5.56mm, armor piercing


Ammunition. 5.56mm caliber, armor piercing.

5.56mm, hollow point


Ammunition. 5.56mm caliber, hollow point.

5.56mm, surplus


Ammunition. 5.56mm caliber, surplus.

5.56mm, match


New ammunition added with the add-on, Gun Runners' Arsenal.