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Quick Start
Configure bullet ballistics, select target specifications, set statistical variability parameters, and run Monte Carlo simulation.
Ballistic Parameters
BC (Ballistic Coefficient): Aerodynamic efficiency. Higher = less drift and drop.
Drag: G7 for modern boat-tails; G1 for older/flat-base data.
MV (fps): Muzzle velocity in feet per second.
Weight (gr): Bullet mass in grains.
Diameter (in): Bullet caliber in inches (also used for line-breaking scoring).
Length (in): Bullet length in inches.
Twist (in/turn): Barrel twist rate (e.g., 8 for 1:8 twist).
Spin Effects: Includes spin drift and crosswind jump for realism.
Target & Match Parameters
Target Type: Standard competitive targets with specific ring diameters. SR (200-300yd), MR (300-600yd), LR (800-1000yd). FCA variants are custom-designed targets optimized for F-Class shooting with different ring proportions.
Range: Distance to target in yards.
Shots/Match: Number of rounds per match.
Matches: Number of complete matches to simulate. Higher values improve statistical significance but increase computation time.
Variability Parameters (Standard Deviations)
MV σ (fps): Spread in muzzle velocity (lower = more consistent).
Cross Wind σ (mph): Side-to-side wind variability (main driver of horizontal spread).
H/T Wind σ (mph): Head/tail variability (small influence on drop).
Vert Wind σ (mph): Up/down air movement (usually minor).
Accuracy (MOA): Rifle+shooter precision; 1 MOA ≈ 1" at 100 yd.
Environmental Parameters
Altitude: Height above sea level in feet. Affects air density - higher altitude = less air resistance. Pressure is estimated using a standard atmosphere model. Sea level: 0 ft, high altitude: 5000+ ft.
Temperature: Air temperature in Fahrenheit. Affects air density - higher temperature = less dense air. Standard: 59°F, range: -20°F to 120°F.
Humidity: Relative humidity percentage. Higher humidity = slightly less air resistance (water vapor is lighter than dry air). Typical: 20-80%, affects bullet performance minimally.
Simulation Results
Estimated Score: Running average of total points and X-ring hits across all completed matches (based on shots per match setting). This estimate converges to the true average as more iterations are completed. Updates continuously as simulation progresses. Example: "585-27x" = 585 total points with 27 X-ring hits.
Progress Display: Shows "Shots: XXX/YYY" indicating current shots processed vs total shots to simulate.
Target Visualization: Red dots represent bullet impact points. Click on any dot to see detailed hit information (coordinates, score, ring). Use mouse wheel to zoom, drag to pan.
Technical Notes
Monte Carlo: Per‑shot draws from statistical distributions (velocity, wind, accuracy). Wind/MV treated as normal with clipping for outliers; accuracy modeled as a uniform circle in MOA for simplicity.
Trajectory Engine: Same WebAssembly core as the Ballistic Calculator (RK2 integration). 4DOF with simplified spin effects available for realism.
Scoring: Competitive target specs with line-breaking; bullet diameter is used to determine ring breaks on boundaries.
Known Limitations
This list is not exhaustive. Additional limitations, errors, or inaccuracies may exist.
Simplified Wind Model: Wind is drawn independently for each shot from Gaussian distributions (clipped to 3-sigma). Wind remains constant throughout each shot's trajectory. Real wind varies along the bullet path and has temporal correlation between shots not captured here.
Accuracy Model: Rifle accuracy is modeled as a uniform distribution within a circle (diameter = accuracy MOA). Real dispersion patterns may differ and are typically not uniform.
Statistical Tool: This simulator is for exploring statistical patterns, not predicting real-world scores. Do not rely on these simulations for any purpose where incorrect data could be hazardous.
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