M199 assault rifle

The M199 was the official infantry weapon of the U.S. Army.

Gameplay
Firing standard 5.56mm rounds, the gun was described as the "most well-recognized weapon in the modern U.S. Military arsenal" before the Great War. It was known to make a distinctive sound when ejecting a spent shell, leading it to be nicknamed "the Backtalker." It was displayed as part of a museum exhibit on loan from the International Ordnance Museum at the Museum of Technology in Washington D.C.

Appearances
The M199 is mentioned in Fallout 3 and Creation Club content.

Behind the scenes
The "Army, Atom Cats, Gunners and Vault-Tec Weapon Paint Job" and "Brotherhood of Steel, Institute, Railroad, Minutemen Weapon Paint Job" Creation Club bundles, created by community modder Skidabaa in collaboration with Bethesda, identify the assault rifle appearing in Fallout 4 as the M199. The name can be seen when the "drum magazine" modification is applied to the weapon while one of the relevant paints is applied.