A shotgun, also called a "scattergun", is a firearm designed to shoot a multitude of lead or steel balls of varying sizes. This makes it very effective at hunting game, greatly increasing the weapon's hit potential. However, the accuracy and power found at close range diminish rapidly as you get farther away from the target. Shotguns designed for military use are often called "combat shotguns".
The sawed-off shotgun is a break action, 12 gauge shotgun that fires both shells at a time. Each shot delivers 14 pellets (instead of the typical 7), and while its damage-per-second is low, it inflicts good burst damage at close range.
This weapon, like all other shotguns, has a large weapons spread. In fact it has the largest spread of all weapons, so much so that in order to gain the high damage of its shot, you have to fire it at point blank range so that all the pellets hit the intended target.
Furthermore, it is also considered an improved holdout weapon, and can be concealed and taken into weapon-free locations so long as your Sneak skill is 50 or greater.
The sawed-off shotgun can fire a total of about 395 times, or 790 standard rounds, the equivalent of 395 reloads, from full condition before breaking. This amount is exactly the same as its unique variant.
Sloan - In the worker barracks in a easy-locked cabinet.
HELIOS One - In the toolbox in the room with the pool table in main building.
Ralph of Mick & Ralph's carries a nearly 100% condition sawed-off shotgun.
Mick sells many sawed-off shotguns in his secret stash (Speech check 30) and they are in seemingly different conditions. However, upon purchasing, all of the shotguns are nearly broken, despite what is indicated by the store.