Home > Borderlands 3 > Unlock One Pump Chump

How To Unlock One Pump Chump Legendary Gun In Borderlands 3

+1000 Weapon Damage

One Pump Chump is a very powerful Weapon in Borderlands 3, with over +1400 Weapon damage, 3.5x Zoom and 50% chance not to consume ammo when fired this weapon is a true killing machine. One Pump Chump can be unlocked by defeating the One Punch Pschyo who spawns near New-U Station. In this Borderlands 3 Weapon guide, you can find a solution where to find One Pump Chump gun and how to unlock this powerful legendary weapon.

How To Get One Pump Chump Gun


You will need to visit Promethea Planet to find One Pump Chump Gun. Go to New-U Station in Lectra City and find the subway near the station. Enter it, and look for a narrow corridor on the left of the first area. There will be some enemies in this region, clear them. Kill everyone before you get in contact with the boss, his damage is very high and these small enemies will annoy you in the fight.

After this, you will have to solve a small puzzle to unlock the door. The puzzle solution is listed below. After unlocking kill One Punch Psycho and he will drop the gun. Use it against the bosses in the game. The weapon can have only 1 bullet but due to 50% chance not to consume ammo when fired, you might get additional shots for free.

How to Solve The Puzzle To Spawn One Punch Psycho


To unlock the door you have to do four things, interact with the leftmost button, then go right and turn the valve. On the right of the valve on the ground there is a lever, pull it and return back to the safe door, draw the lever up on the right side. This is enough to unlock the safe. Most of the time you will get the gun after killing the psycho but if you are not getting it then exit the game right at the point and respawn. Go back to the same place again and repeat the complete process.

One Pump Chump Weapon Stats:

  • Damage: 192
  • Accuracy: 89%
  • Handling: 61%
  • Reload Time: 1.1s
  • Fire Rate: 1.61/s
  • Magazine Size: 1
  • +1425% Weapon Damage
  • 3.5x Weapon Zoom
  • 50% chance not to consume ammo when fired


How to kill One Punch Pschyo

The only way to take down One Punch Psycho is by using a high DPS weapon and dodging at the right time. The enemy refers to famous anime character One Punch Man who has a superpower of killing anyone in one punch. So get a good weapon first, and dodge way at the right time before the enemy punches you to death. With one single punch, you will die so be ready to dodge whenever possible. If you can maintain a good distance then it will be easy for you to kill One Punch Psycho.