{
"id": "xref_g7_crosswind",
"description": "G7 .308 175 gr flat-fire, 8 m/s wind FROM THE LEFT (engine wind_angle = 3pi/2), no twist. Crosswind drift with the opposite sign.",
"source": {
"kind": "cross-implementation",
"citation": "py-ballisticcalc 2.2.10 (open-source point-mass solver; default RK4 engine; standard G1/G7 drag tables). Flat-fire, horizontal-LOS geometry maps py-bc height/windage/velocity/time onto engine McCoy drop/drift/speed/tof; wind direction_from = engine wind_angle + 180 deg.",
"retrieved": "2026-07-15",
"generator_version": "py-ballisticcalc==2.2.10 via data/validation/generators/gen_pybc_refs.py"
},
"inputs": {
"muzzle_angle_rad": 0.0,
"shooting_angle_rad": 0.0,
"twist_rate_in": 0.0,
"is_twist_right": true,
"sight_height_m": 0.0,
"muzzle_height_m": 0.0,
"altitude_m": 0.0,
"temperature_c": 15.0,
"pressure_hpa": 1013.25,
"humidity_frac": 0.0,
"wind_speed_mps": 8.0,
"wind_angle_rad": 4.71238898038469,
"vertical_wind_mps": 0.0,
"use_enhanced_spin_drift": false,
"enable_advanced_effects": false,
"muzzle_velocity_mps": 800.0,
"bullet_mass_kg": 0.01134,
"bullet_diameter_m": 0.0078232,
"bullet_length_m": 0.031496,
"bc_value": 0.243,
"bc_type": "G7"
},
"expectations": [
{
"observable": "drop_m",
"range_m": 400.0,
"value": -1.541119,
"tolerance_justification": "Drop: bounded by RK45(engine, adaptive) vs RK4(py-bc, fixed-step) integration and the two distinct G1/G7 table resolutions/interpolants. 1 cm floor + 0.8% brackets the observed ~0.04% cross-solver difference with ~20x head-room while failing a >~1% (field-noticeable, ~1 MOA at long range) drop regression.",
"tol_abs": 0.01,
"tol_rel": 0.008
},
{
"observable": "drift_m",
"range_m": 400.0,
"value": 0.73598,
"tolerance_justification": "Wind drift: a difference of larger integrated quantities, so it inherits both the drag-curve and time-of-flight gaps; observed cross-solver difference ~0.1%. 2 cm floor + 2% keeps ~20x head-room and fails a >~2.5 cm-per-metre-of-drift regression.",
"tol_abs": 0.02,
"tol_rel": 0.02
},
{
"observable": "tof_s",
"range_m": 400.0,
"value": 0.591997,
"tolerance_justification": "Time of flight: integrator + drag-curve differences accumulate in flight time; observed cross-solver difference ~0.03%. 3 ms floor + 0.6% keeps ~15x head-room.",
"tol_abs": 0.003,
"tol_rel": 0.006
},
{
"observable": "drop_m",
"range_m": 800.0,
"value": -8.171282,
"tolerance_justification": "Drop: bounded by RK45(engine, adaptive) vs RK4(py-bc, fixed-step) integration and the two distinct G1/G7 table resolutions/interpolants. 1 cm floor + 0.8% brackets the observed ~0.04% cross-solver difference with ~20x head-room while failing a >~1% (field-noticeable, ~1 MOA at long range) drop regression.",
"tol_abs": 0.01,
"tol_rel": 0.008
},
{
"observable": "drift_m",
"range_m": 800.0,
"value": 3.593676,
"tolerance_justification": "Wind drift: a difference of larger integrated quantities, so it inherits both the drag-curve and time-of-flight gaps; observed cross-solver difference ~0.1%. 2 cm floor + 2% keeps ~20x head-room and fails a >~2.5 cm-per-metre-of-drift regression.",
"tol_abs": 0.02,
"tol_rel": 0.02
},
{
"observable": "tof_s",
"range_m": 800.0,
"value": 1.44921,
"tolerance_justification": "Time of flight: integrator + drag-curve differences accumulate in flight time; observed cross-solver difference ~0.03%. 3 ms floor + 0.6% keeps ~15x head-room.",
"tol_abs": 0.003,
"tol_rel": 0.006
}
]
}