Hunting for legendary gear is a core part of the Borderlands 3 experience, and some weapons stand out due to their unique pop-culture references and extreme power. Among these sought-after firearms, the One Pump Chump is a legendary shotgun that provides incredible single-shot damage early in the game. Finding this powerful weapon requires navigating a specific subway system and solving a clever environmental puzzle.
Navigating to Lectra City on Promethea
To begin your hunt for this legendary shotgun, you must travel to the planet Promethea and enter the Lectra City sector. Once you arrive at the main fast travel station, head toward the southern portion of the map near the Typhon log. Look for a large set of stairs that leads down into an abandoned subway station filled with hostile bandits.
After clearing out the initial group of enemies, follow the underground train tracks heading back toward the northern section. Keep a close eye on the left side of the tunnels until you spot a narrow hallway leading into a small room. This hidden alcove contains a locked door surrounded by five deactivated television screens.
Solving the Subway Door Puzzle
Unlocking the door to face the mini-boss requires interacting with a specific set of buttons, levers, and valves located in the room directly opposite the television screens. You must trigger these interactive objects in the correct sequence to power up all five screens simultaneously. The correct order involves pressing the leftmost button on the padlock, turning the valve on the right, pulling the lever next to the valve, and finally flipping the switch on the nearby box.
Once all five televisions light up, the heavy security door will swing open to reveal a unique Easter egg enemy. A powerful Psycho named One Punch will walk out of the room to confront you immediately. Be extremely cautious during this encounter, as his devastating melee strikes can take down your shields and health in a single hit.
Defeating One Punch and Farming the Shotgun
Defeating One Punch requires keeping a safe distance and kiting him around the subway corridors while chipping away at his health bar. He does not possess a massive health pool, but his high movement speed makes him a lethal threat if you get cornered. Once he is defeated, check the surrounding floor carefully to see if he dropped the legendary prize.
The One Pump Chump is an exclusive drop from this specific mini-boss, meaning it cannot be found as a standard world drop elsewhere. If the weapon does not appear on your first attempt, simply save your progress and exit to the main menu. Reloading your session will reset the Lectra City zone, allowing you to run down the subway stairs and trigger the puzzle encounter again.
Weapon Mechanics and Performance
The One Pump Chump is a high-tier shotgun manufactured by Jakobs that completely alters standard combat strategies. It typically boasts a massive weapon damage bonus that often exceeds 1,000 percent, making it exceptionally lethal for landing critical hits on enemy weak points. This unparalleled damage output allows players to defeat standard combatants with a single well-placed shot.
To balance its extreme firepower, the shotgun features a magazine capacity of only one round before requiring a reload. However, it also comes with a unique passive perk that grants a 50 percent chance to not consume ammo when fired. This special mechanic allows lucky players to chain multiple high-damage shots together without experiencing a delay in their offensive rhythm.