Independent Fallout Wiki Overview Article 
The .308 round is a type of ammunition in Fallout 3, Fallout: New Vegas, Fallout 4, and Fallout 76.
Background
The .308 caliber rounds were a full-size rifle cartridge, used primarily in hunting rifles in the United States before the Great War.[1] Brands include Circle G and Grandad's.
Variants
.308 round
.308 armor piercing
Gameplay article: Fallout: New Vegas
.308 JSP
Gameplay article: Fallout: New Vegas
.308 hollow point
Gameplay article: Fallout: New Vegas
Ultracite .308 round
Gameplay article: Fallout 76
Ultracite .308 rounds deal increased damage to Scorched enemies and are exclusively used by compatible weapons with prime receivers. They cannot be found in the world and are only available via crafting at a tinker's workbench.