This section is needed but has not been written yet. You can help Nukapedia by writing it.
Weapon modifications will modify an existing weapon, and any modifications previously equipped on the weapon will be destroyed, not unequipped. Loose mods cannot be crafted.
Known by default
Standard propellant tank (1)
Crafted at a weapons workbench.
A loose mod exists in the game files, but cannot be found in-game.
This article is too short to provide more than rudimentary information about the subject. You can help Nukapedia by expanding it.