Fallout 4: Prototype UP77
Location guide for legendary laser rifle ‘Prototype UP77’ with unlimited ammo capacityYouTube

Fallout 4 fans can now enjoy the rare unlimited ammo potentials of legendary laser rifle Prototype UP77 as renowned YouTuber MrBossFTW (aka Ross) has revealed the location guide for the weapon. As Ross admits in his latest gameplay video, the Prototype UP77 is one of the only two guns that supports unlimited ammo capacity in the game.

Here is how you can get this rare and powerful weapon for free:

  • Just travel to the location on the in-game map called University Point, which is in the south-east portion (towards the bottom) of the commonwealth map.
  • It is advisable to bookmark this location if you are visiting the place for the first time. Besides, you will need the master lock-picking skill to access this secret weapon. In case your lock-picking skill level is not up to the mark, you could always come back later using the bookmarked location on the map to get the weapon.
  • Once you reach the University Point, you will stumble upon a giant "Bank" sign at the building's front entrance and the door at the bank reads University Credit Union. Do not enter through this door. Instead, walk past the left wall of the bank and head into the opening on the side entrance.
  • You will find a bunch of cash registers with some money in there along with a few other collectibles strewn around.
  • Move forward until you find the terminal on the wall, which is placed near the room's staircase -- adjacent to a metal door in the room.
  • You are required to hack into the Navis terminal by guessing the right password. Once you get it right, the door to the bank vault will be unlocked.
  • Once you enter the University Credit Union, you will find more cash registers, some money and a few safe deposit lockers.
  • Then, head down to the bottom of the University Credit Union to access another Navis terminal. Remember to "quick save" your game and if something goes wrong, you can always reload the game from the last saved checkpoint.
  • Once you unlock the second vault door, you will get access to some ammo boxes and large stashes of money hidden in safes. You will need to unlock three safes including two Master safes and one Advanced safe.
  • One of the master safes will have a bright red button. Hit the button to unlock a mysterious hidden door on the wall. This will lead you into the generator room.
  • Now you will find the secret legendary weapon, Prototype UP77, sitting right there on the table along with a bunch of fusion cells, just beside a terminal. Do remember to grab these fusion cells which will serve as ammo for the laser rifle.

Tip 1: The UP77 does a damage of 61 with fire-rate of 50, range of 227 and accuracy of 96. The weapon weighs 6.5lbs with a selling price of 355 bottle caps.

Tip 2: The legendary laser rifle supports unlimited ammo capacity, which means you can fill in as many rounds of fusion cells as you collect through the game. In other words, you don't have to reload the gun until the time its barrel runs out of ammo and you have to manually insert more fusion cells into it.