Getting that weapon to its max level is an important thing to do in The Last of Us. Not only it will make the weapons in your arsenal more powerful, it will also increase your chances to survive against the enemies in the game. In order to max out your weapons, you must first find a bunch of parts and a workbench.
In the Last of Us, the only place you are able to upgrade weapons is through a workbench. Unfortunately, there are a only a few available, therefore where you see a workbench, it’s best to use them. Here is a list of locations where you can find all of the workbenches.
The first workbench will be on the bottom floor of the museum, just after escaping the infected through the garage door.
Go to the Church basement.
Inside the upper first building of the hunter’s camp.
Near the office behind hotel restaurant’s kitchen.
Located in the Financial District. Use the cart to climb over the vending machine.
Inside the opened garage door.
Left side of the dam control room
Inside the depot.
Inside the Science lab, the workbench is located left from the entrance of the building.
Located in the Triage Area in the far tent.
After Ellie first lets you in, you’ll find the workbench in the first room of the Hospital Tunnel Ventilation System.