Compare calibers

Example response

{
  "success": true,
  "data": {
    "items": [
      {
        "id": "9x19mm-parabellum",
        "name": "9x19mm Parabellum",
        "aliases": [
          "7.62x51mm NATO",
          ".308 Win"
        ],
        "natoDesignation": "9mm NATO",
        "bulletDiameterMm": 9.01,
        "neckDiameterMm": 9.65,
        "baseDiameterMm": 9.93,
        "rimDiameterMm": 9.96,
        "rimThicknessMm": 1.27,
        "caseLengthMm": 19.15,
        "overallLengthMm": 29.69,
        "bulletLengthMm": 15.5,
        "maxPressureMpa": 235,
        "maxPressurePsi": 34084,
        "typicalBulletWeightG": 7.45,
        "typicalMuzzleVelocityMps": 360,
        "typicalMuzzleEnergyJ": 481,
        "primerType": "small_pistol",
        "cartridgeType": "rimless",
        "caseShape": "tapered",
        "caseMaterial": "brass",
        "projectileKind": "bullet",
        "bulletProfile": "round_nose",
        "closure": "bullet",
        "yearIntroduced": 1902,
        "designer": "Georg Luger",
        "specSource": "https://en.wikipedia.org/wiki/9%C3%9719mm_Parabellum",
        "specStandard": "cip",
        "dataConfidence": 0.9,
        "verifiedAt": "2026-09-08",
        "verifiedFields": [
          "case_length_mm",
          "max_pressure_mpa"
        ],
        "createdAt": "2025-01-15 12:00:00",
        "updatedAt": "2026-09-10 06:42:19",
        "version": "a3f1c2d4e5b6a7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2",
        "provenance": {
          "sources": [
            "https://www.glock.com/en/products/pistols/g17-gen5"
          ],
          "sourceKinds": [
            {
              "url": "https://www.glock.com/en/products/pistols/g17-gen5",
              "kind": "manufacturer",
              "archivedFrom": null,
              "rank": 0,
              "tier": "authority",
              "basis": "declared",
              "evidence": null
            }
          ],
          "makerSource": "https://www.glock.com/en/products/pistols/g17-gen5",
          "evidence": "maker",
          "checks": {
            "raised": 3,
            "history": [
              {
                "task": "verify:firearms:glock-g17-gen5",
                "number": 1204,
                "check": "quality:firearm-weight-fits-its-size",
                "kind": "verify",
                "agent": "redback",
                "worker": "redback-046535",
                "status": "resolved",
                "decidedAt": "2026-09-25 07:42:39",
                "proposed": "Read https://us.glock.com/en/pistols/g17-gen5: agrees on barrel_length, weight.",
                "fields": [
                  "barrel_length_mm",
                  "weight_empty_g"
                ],
                "sources": [
                  "https://us.glock.com/en/pistols/g17-gen5"
                ],
                "finding": {
                  "why": "2.22 g/cm3 against a submachine-gun / carbon-steel median of 0.64; check the weight and the dimensions",
                  "evidence": {
                    "apparentDensity": 2.218,
                    "categoryMedian": 0.635
                  }
                }
              }
            ]
          },
          "dataConfidence": 0.95,
          "verifiedAt": "2026-09-08",
          "verifiedFields": [
            "barrel_length_mm",
            "weight_empty_g"
          ],
          "updatedAt": "2026-09-08 04:10:22",
          "version": "ba5c1d9e06c279a5"
        }
      }
    ],
    "deltas": [
      {
        "field": "caseLengthMm",
        "values": [
          19.15
        ],
        "min": 19.15,
        "max": 26.75,
        "percentDiff": 39.7
      }
    ]
  }
}