The Vault - Fallout Wiki

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The Vault - Fallout Wiki
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For an overview of 5.56mm ammunition throughout the Fallout series, see 5.56mm round. For an overview of .223 caliber ammunition throughout the Fallout series, see .223 round.
Mag. Size
Weight1 lbValue$
Mini-FOT Logo.pngThe following is based on Fallout Tactics and some details might contradict canon.

5.56mm is a type of ammunition in Fallout Tactics.


The following section is transcluded from 5.56mm round. To modify, please edit the source page.

The 5.56x45mm round is a rifle cartridge derived from the .223 Remington, originally developed for the M16 service rifle of the United States Army.[1][2] 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.

The standard type of 5.56mm ammunition, offering good performance to the shooter. Popular among civilians and soldiers alike, it is by far one of the most popular rounds in the wastelands. It can generally be used interchangeably with its parent round, the .223 Remington, due to the same casing, though some weapons might not be rated for the military-grade ammo. In such a case, the 5.56x45mm round can cause dangerous buildup of pressure inside the receiver.


The workhorse of the Eastern Brotherhood and the player's team, likely to see plenty of use until more powerful weapons become available.

Weapons using this ammunition


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  1. Vault Dweller's Survival Guide p.5-17: "Rifle caliber ammunition. The FMJ stands for Full-Metal Jacket, which describes the bullet that is used in the round of ammo. A FMJ bullet is very tough, and has pretty good penetration without sacrificing good expansion. In other words, it‘s an average round."
  2. Fallout Official Survival Guide p.119: ".223 Full Metal Jacket (FMJ): This is the same ammo used in the late 20th century by various military rifles, including the M-16. A good, basic, hard-hitting round."