Prototype UP77 "Limitless Potential"

The Prototype UP77 "Limitless Potential" is a unique weapon in Fallout 4.

Characteristics
This unique laser rifle features unlimited ammo capacity and never requires reloading unless the player runs out of fusion cells. The magazine size is equal to all fusion cells currently in inventory.

The UP-77 prototype does consume ammunition at a normal rate, it merely never needs reloading.

The player character needs the Science! perk to improve this weapon.

Weapon modifications
The specific weapon modifications fitted to the gun when found are level dependent and will vary.

Locations
The UP77 is found in University Credit Union at University Point. Inside the Credit Union, one will find a bank vault with a Novice terminal. After hacking and opening the vault's door, the Sole Survivor will be in a room with some lockpick-able safes. On the 2nd row, there will be a master locked safe; opening the safe will reveal a red button. Pressing it will open a wall to the right and on the large table in the middle of the room will be the UP77.

Variants

 * Laser gun
 * Old Faithful, a unique laser pistol that does double damage if the target is at full health. It is sold by Arturo Rodriguez in Diamond City.
 * Survivor's Special, a unique laser rifle that deals more damage the lower your health is. It is a potential reward for completing the quest The Lost Patrol. It is also possible to steal the item from Paladin Brandis, before the The Lost Patrol quest ends.
 * Good Intentions, a unique laser rifle that, on critical hits, causes targets to frenzy. It is carried by Clint.
 * Righteous Authority, a unique laser rifle, given as a reward for completing the Call to Arms quest. It's critical hits do double damage and the critical meter fills 15% faster.
 * Wazer Wifle, a unique Laser rifle similar to the Prototype UP77 "Limitless Potential", it is given as a reward for completing three unmarked quests for Shaun after ending the main quest with any faction.