Gungeon Guide

Bullet That Can Kill the Past Guide

2026-07-13

The Bullet That Can Kill The Past is built from four components hidden across Enter the Gungeon — collecting them lets each Gungeoneer kill their past, which is required for the true ending.

Bullet That Can Kill the Past Guide

The Bullet That Can Kill The Past is a passive item assembled from four components spread across four floors of Enter the Gungeon. Once built by the BlacksmithBlacksmith in the Forge, it allows any Gungeoneer to enter and confront their past. It can be obtained from the BlacksmithBlacksmith an unlimited number of times after it has been built once.

The sections below follow the order how to forge it → where each of the four pieces is → how to use it → things to watch out for. The four pieces are independent and progress is permanent, so there is no need to gather them all in a single run.

How to build the Bullet

Collect all four components across separate floors and bring each one to the BlacksmithBlacksmith in the Forge. The components do not need to be delivered in a single run — each one you hand in is remembered permanently.

Components

/wiki-images/prime-primer.webp Prime Primer

Prime PrimerPrime Primer — Found in Gungeon. Purchase it for 110 coins from BelloBello's shop.

  • Discount items do not reduce its price.
  • It is locked in a glass display case and cannot be stolen with the Grappling HookGrappling Hook.

/wiki-images/arcane-gunpowder.webp Arcane Gunpowder

Arcane GunpowderArcane Gunpowder — Found in Mines. A large empty-looking room contains invisible minecart rails over a chasm. Ride the minecarts and dodge-roll between them to cross.

  • The Arcane GunpowderArcane Gunpowder is the only active item among the four components — consider using the PilotPilot (character differences: see All Characters Guide: Starting Loadouts & TraitsAll Characters Guide: Starting Loadouts & Traits), who carries an extra active slot, when transporting it to the Forge.
  • If you have a flight item such as Wax WingsWax Wings, you can simply fly over the chasm.
  • You can slow down a minecart and stop it beside the next one to make jumping across easier.
  • Falling into a pit in this room resets the entire room, deleting any dropped items.

/wiki-images/planar-lead.webp Planar Lead

Planar LeadPlanar Lead — Found in Hollow. A room with a chasm hides an invisible path to the item.

  • Shoot and reload to drop shells — they land on invisible solid ground and mark safe tiles. Starting guns work especially well since they eject shells backwards.
  • Guns that leave liquid or debris on the ground, such as Fossilized GunFossilized Gun or Mega DouserMega Douser, will reveal the path.
  • With Amulet of the Pit LordAmulet of the Pit Lord, trial and error is a viable method since there is no penalty for falling off the path.
  • Any flight item (Wax WingsWax Wings, JetpackJetpack, Balloon GunBalloon Gun, Ring of Ethereal FormRing of Ethereal Form, Cat Bullet King ThroneCat Bullet King Throne) lets you cross the chasm without needing the path at all.
  • The Grappling HookGrappling Hook or Directional PadDirectional Pad can be used to cross the chasm or snag the item itself.
  • Bloodied ScarfBloodied Scarf can also cross the chasm — hold down roll while standing at the very edge of the ledge to charge a blink to the other side.
  • If you fall off the path, it will be randomly regenerated.

/wiki-images/obsidian-shell-casing.webp Obsidian Shell Casing

Obsidian Shell CasingObsidian Shell Casing — Defeat the DragunDragun, then destroy its skull to reveal the casing.

  • This is the only component that cannot be stolen by the Resourceful RatResourceful Rat.
  • It can also be re-acquired after giving it to the BlacksmithBlacksmith, making it the only component obtainable more than once.

Using the Bullet

Once you have the Bullet That Can Kill The Past in your inventory, the Gun That Can Kill The Past appears at the end of a floor. Shooting yourself with it lets you enter your Gungeoneer's past. The Bullet cannot be dropped.

You must have the Bullet before entering the Aimless Void — it is not possible to retrieve it once you cross that threshold.

Notes

  • Carrying the Bullet is not required to access Bullet Hell or fight the LichLich.
  • The Resourceful RatResourceful Rat can steal the Bullet. With Ring of the Resourceful RatRing of the Resourceful Rat, it can be traded for an S-tier passive item.
  • Using the Gun That Can Kill The Past without the Bullet will still let you shoot yourself and reach the credits screen — but the run ends there instead of entering your past.
  • Having CloneClone when you die and possess the Bullet has no additional effect.
  • All rooms guaranteed to spawn because of a component will no longer appear after that component has been turned in.
  • SpiceSpice can replace the Prime PrimerPrime Primer in the shop if enough SpiceSpice has been used.
  • If your co-op partner dies during the DragunDragun fight, they lose the Bullet upon revival — but they can still fire the Gun That Can Kill The Past at themselves to enter the past.