The shotgun in The Last of Us 2 is an excellent weapon for attacking stronger infected and for dealing with opponents quickly at a close range. This guide page has information on how to get a shotgun in TLoU2. and explain whether it is possible to produce ammunition for a shotgun.
A shotgun for Ellie
The first chance of getting a shotgun for Ellie appears during the Seattle Day 1. You must advance to the Downtown stage, which is the biggest location in the game. Downtown is a partially opened location - you can move around a large area and visit multiple places.
One of the optional locations you can visit is the ruined Westlake Bank headquarters - we have shown it in the pictures above.
After moving through the rubble, you reach the ruined lobby of the bank. You will come across a group of infected.
Win the confrontation and go to the room at the back of the bank where the vault is located. Open it by solving a mini-puzzle - the combination to the vault is 60-23-06. You can read it from a note found in the bag.
Inside the vault, you will find several unique treasures. Among them is Pump Shotgun found next to the corpse of one of the men who tried to rob the bank.
This isn't the only place where you can get a shotgun. This is simply a way to start using it as early as possible. You can also find a shotgun, for example, on the corpses of some of the defeated enemies.
A shotgun for Abby
Abby (the second playable character) can also get a shotgun, though this will be a different model from the one used by Ellie - Abby's weapon is a Double Barrel Shotgun.
You can get this shotgun during the Hostile Territory stage. It is one of the missions that are part of Abby's Seattle, Day 1 chapter.
You can get the shotgun soon after you reach the area in the picture. There are a few shops on the sides of this alley you can visit.
Enter the Ruby Dragon building, head to the upper floor, and deal with the monsters. Then go to the large balcony. You have to jump to the building located on the opposite side of the street.
Get to the ground floor of that building. The shotgun is hidden under the shop counter.
A unique feature of Abby's shotgun is that it can use incendiary ammunition which can be crafted. However, you can do that only after finding Training Manual: Firearms.
This manual can be found in the Forest stage, which is one of the later missions of the Seattle, Day 1 chapter. This secret can be found soon after you escape monsters and defeat the tall woman who got Abby's weapons. Reach La Rosa's Auto Shop and go inside it. For more details on how to find the training manual, see the Training manuals and passive skills page.
The ability to make ammunition is the first of that tree - Craft Incendiary Shells. It costs 20 supplements. Once you have acquired the skill, you can craft 2 shells by spending 1 alcohol and 1 explosive.
We also recommend getting this skill's upgrade - Craft more incendiary shells. It will allow you to craft 3 shells at the same time and increase your inventory limit to 6 (default is 4).
Incendiary shells for a shotgun are especially useful against the infected. Even if the monster doesn't die immediately, it will gradually lose its health points. There is also a chance that it will stop attacking for a short time. You can take advantage of that and, for example, kill it with a pistol or other weapon.