In Iron Soul, the “blueprint” most likely refers to a skin/item unlock shown in the Gunsmith menu rather than a world pickup. The clue from a recent player clip says to open Gunsmith , select Receiver , then right-click and open Skins to find it there.

Where to check

  • Open Gunsmith.
  • Go to Receiver.
  • Right-click it.
  • Select Skins.
  • Look for the blueprint there.

Notes

  • I did not find a separate confirmed map location for a blueprint pickup in Iron Soul from the available result, so this looks like a menu unlock/use case rather than a hidden chest item.
  • If you meant a different blueprint in the Roblox game, the name of the item matters because Iron Soul guides often mix up skins, recipes, and weapon parts.

What to try next

  • Check your Gunsmith/Receiver skins first.
  • If it is still missing, look for the exact item name in the game’s Discord or guide pages, since some unlocks may be tied to codes, progression, or specific drops.

TL;DR: the blueprint is most likely in Gunsmith → Receiver → Skins , not on the map.