[
  {
    "type": "item_group",
    "id": "rare",
    "magazine": 100,
    "subtype": "distribution",
    "entries": [
      { "item": "double_plutonium_core", "prob": 50 }
    ]
  },
  {
    "type": "item_group",
    "id": "nanofab_recipes",
    "magazine": 100,
    "subtype": "distribution",
    "entries": [
      { "item": "double_plutonium_core", "prob": 10 }
    ]
  }
]