GunSpec

Ammunition

Query individual ammunition loads, retrieve ballistic trajectory tables, calculate firearm-specific performance, and load firearms with full ballistic profiles. Essential for ballistic simulation, ammunition databases, and game development.

Auth RequiredBuilder+

Computes velocity, energy, and drop at the requested distances for one load, optionally adjusted for a specific barrel length.

GET/v1/ammunition/{id}/ballistics

  • stringheaderrequired

    Your API key. Authorization: Bearer <key> is accepted in its place.

  • stringrequired

    Ammunition load slug

    Accepts
    a lowercase slug: letters, digits and hyphens
    Example

  • number

    Barrel length to adjust muzzle velocity for

    Range
    50 – 2000
    Example
  • string

    Comma-separated distances in metres

    Example

  • object

    The response payload.

  • object

    The load the figures are for.

  • string

    Slug of the load the table was computed for.

  • string

    Display name, as the maker writes it.

  • string

    Slug of the cartridge. Resolve against /v1/calibers/{id}.

  • number | null

    Barrel length in millimetres, measured from the breech face.

  • number

    Muzzle velocity in metres per second, for the default load.

  • number

    Muzzle energy in joules, for the default load.

  • number

    Effective range in metres against a point target.

  • TerminalBallistics

    Terminal performance indices computed at the muzzle.

  • number

    Taylor Knock-Out factor.

  • number

    Momentum in kilogram-metres per second.

  • number

    Bullet mass divided by the square of its diameter. Higher penetrates better, all else equal.

  • number

    Hatcher Relative Stopping Power.

  • number

    Energy per unit frontal area, in joules per square centimetre.

  • TrajectoryPoint[]

    The solution sampled at each requested distance.

  • number

    Distance from the muzzle in metres.

  • number

    Remaining velocity at this distance, in metres per second.

  • number

    Remaining energy at this distance, in joules.

  • number

    Bullet drop below the line of sight at this distance, in centimetres.

  • number

    Time of flight to this distance, in seconds.

  • number

    Velocity as a multiple of the speed of sound. Below ~1.2 the projectile is transonic and destabilises.

  • number

    Momentum in kilogram-metres per second.

  • number

    Taylor Knock-Out factor at this distance.

  • number

    Energy per unit frontal area, in joules per square centimetre.

  • 400VALIDATION_ERRORValidation error
  • 401UNAUTHORIZEDAPI key required
  • 403FORBIDDENValid key, not permitted
  • 404NOT_FOUNDResource not found
  • 429RATE_LIMITEDRate limit exceeded
  • 500INTERNAL_ERRORUnexpected server error

Requires Builder tier or higher.

If barrel_length_mm is provided, muzzle velocity is adjusted based on barrel length relative to the reference barrel.

Default distances are 0, 100, 200, 300, and 500 meters. Maximum 20 distance points per request.

Trajectory calculations use a G1 drag model with standard atmospheric conditions (15C, 1013 hPa, sea level).

Minimum tier
Builder+
Monthly quota
25,000/mo
Rate limit
60/min
Daily cap
2,000

Figures shown are for this endpoint's minimum tier. Higher tiers raise every limit.