GunSpec

All 39 single-call tools

Ammunition per kilogram

  • gunspec_ammo_load
  • Builder
  • Read-only

Returns how much ammunition one to five firearms carry per kilogram: rounds per kilogram of full magazines and how many full magazines fit a weight budget, derived from each firearm's loaded and empty weights, and the estimated mass of a basic load of rounds and magazines from a fitted cartridge-mass model. Derived and estimated figures are labelled; always say which a figure is, and give an estimate with its range. A warning beside a magazine means the catalog's weights for it look wrong.

Example usage

  1. 1

    A person asks

    • How many rounds can I carry in 5 kg of magazines for an HK416 against an AK-74?
  2. 2

    The assistant calls the tool

    tools/call
    json
    {  "name": "gunspec_ammo_load",  "arguments": {    "ids": [      "hk416",      "ak-74"    ],    "budget_kg": 5  }}
  3. 3

    The server answers

    Result
    json
    {  "method": {    "id": "ammo-load",    "name": "Magazine arithmetic and the fitted cartridge-mass model",    "equation": "Full magazine m_mag = loaded weight − empty weight (derived); rounds per kg = capacity / (m_mag in kg); magazines in a budget B = floor(B / m_mag). Estimated round m_round = bullet + 2.5 g/cm³ × π/4 × base diameter² × case length, with the…",    "maxErrorPct": 8.5,    "fittedEnvelopeCm3": [      2.6,      5.7    ],    "references": [      {        "name": ".45 ACP",        "load": "M1911 ball",        "roundG": 21.19,        "source": "https://man.fas.org/dod-101/sys/land/m1911-ball.htm"      },      {        "name": "5.56×45mm NATO",        "load": "M855",        "roundG": 12.31,        "source": "https://en.wikipedia.org/wiki/5.56%C3%9745mm_NATO"      },      {        "name": "7.62×39mm",        "load": "57-N-231",        "roundG": 16.3,        "source": "https://en.wikipedia.org/wiki/7.62%C3%9739mm"      }    ]  },  "load": {    "budgetKg": 5,    "magazines": 7,    "rounds": null,    "ammoId": null,    "defaulted": [      "ammo_id",      "magazines",      "rounds"    ]  },  "results": [    {      "firearm": {        "id": "hk416",        "name": "HK416",        "magazineType": "detachable_box",        "magazineCapacity": 30      },      "cartridge": {        "caliberId": "5-56x45mm-nato",        "bulletG": 4,        "bulletSource": "caliber",        "ammunitionId": null,        "envelopeCm3": 3.222      },      "magazine": {        "loadedMagazineG": 400,        "capacity": 30,        "roundsPerKg": 75,        "source": "derived",        "check": {          "verdict": "plausible",          "roundsG": {            "expected": 361.7,            "low": 330.8,            "high": 392.5          },          "bandG": {            "low": 309,            "high": 879.3          },          "source": "estimated"        }      },      "budget": {        "magazines": 12,        "rounds": 360,        "massG": 4800,        "leftoverG": 200,        "source": "derived"      },      "basicLoad": {        "rounds": 210,        "roundG": {          "expected": 12.06,          "low": 11.03,          "high": 13.08        },        "roundsG": {          "expected": 2531.6,          "low": 2315.9,          "high": 2747.3        },        "magazines": 7,        "magazinesG": {          "expected": 3345.3,          "low": 2420.9,          "high": 5897.3        },        "source": "estimated"      },      "delta": null,      "warnings": [],      "error": null    },    {      "firearm": {        "id": "ak-74",        "name": "AK-74",        "magazineType": "detachable_box",        "magazineCapacity": 30      },      "cartridge": {        "caliberId": "5-45x39mm",        "bulletG": 3.43,        "bulletSource": "caliber",        "ammunitionId": null,        "envelopeCm3": 3.127      },      "magazine": {        "loadedMagazineG": 300,        "capacity": 30,        "roundsPerKg": 100,        "source": "derived",        "check": {          "verdict": "lighter-than-rounds",          "roundsG": {            "expected": 337.5,            "low": 308.7,            "high": 366.2          },          "bandG": {            "low": 286.8,            "high": 853.1          },          "source": "estimated"        }      },      "budget": {        "magazines": 16,        "rounds": 480,        "massG": 4800,        "leftoverG": 200,        "source": "derived"      },      "basicLoad": {        "rounds": 210,        "roundG": {          "expected": 11.25,          "low": 10.29,          "high": 12.21        },        "roundsG": {          "expected": 2362.2,          "low": 2160.9,          "high": 2563.5        },        "magazines": 7,        "magazinesG": {          "expected": 3176,          "low": 2265.9,          "high": 5713.5        },        "source": "estimated"      },      "delta": {        "roundsPerKg": 25,        "budgetRounds": 120      },      "warnings": [        "The derived full magazine is lighter than its rounds alone are estimated to weigh, even allowing the model's whole error: one of the record's two weights is wrong, so the figures derived from it are too."      ],      "error": null    }  ]}

    Captured from the live API on Oct 22, 2026. Lists and long text are shortened for display.

Related references

Arguments

  • string[]required

    One to five firearm slugs.

    Sent as
    ?ids=
  • string

    A load whose bullet the estimate uses. Leave it out for each cartridge's typical bullet.

    Sent as
    ?ammo_id=
  • numberdefault5

    A weight of full magazines to fill, in kg.

    Range
    0.1 – 100
    Sent as
    ?budget_kg=
  • integerdefault7

    Full magazines in the estimated basic load.

    Range
    0 – 50
    Sent as
    ?magazines=
  • integer

    Rounds in the estimated basic load. Leave it out for magazines times the capacity.

    Range
    1 – 10000
    Sent as
    ?rounds=

Each argument is sent to GET /v1/firearms/ammo-load as the parameter shown, so the same request can be made to the API directly, with your key, if you want to shape what comes back.

json