Need Help or Found an Issue?
Quick Start
Define your bullet, range, and variability parameters. Choose a circle or rectangle target shape. Click Run to fire the Monte Carlo simulation and view hit probability and dispersion statistics.
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 / Diameter / Length: Bullet geometry and mass used by the trajectory model.
Twist (in/turn): Barrel twist rate (e.g., 8 for 1:8 twist).
Spin Effects: Includes spin drift and crosswind jump for realism.
Target Shape
Circle: Defined by diameter in inches. Hit = impact landing within the circle.
Rectangle: Defined by width and height in inches. Hit = impact landing within the rectangle.
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 is about 1 inch at 100 yards.
Environmental Parameters
Altitude: Height above sea level in feet. Higher altitude reduces air density and drag.
Temperature: Air temperature in Fahrenheit. Warmer air is less dense.
Humidity: Relative humidity percentage. Higher humidity slightly reduces air resistance.
Statistics
Hit Probability: Fraction of shots landing inside the target shape.
Horizontal/Vertical Spread: Max X and Y extent of the group (inches).
Extreme Spread: Maximum distance between any two impacts (inches).
Mean Radius: Average distance from group center (inches).
Radial Std Dev: Standard deviation of radial distances from center (inches).
CEP (50%): Circular Error Probable -- radius of circle containing 50% of shots (inches).
Known Limitations
This list is not exhaustive. Additional limitations, errors, or inaccuracies may exist.
Simplified Wind: Wind drawn independently per shot from Gaussian distributions; constant along trajectory.
Accuracy Model: Uniform distribution within a circle (diameter = MOA setting).
Statistical Tool: This simulator is for exploring statistical patterns, not predicting real-world performance.
Full Disclaimers: See the
Terms of Service for complete safety and liability information.