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Purpose
This tool generates five grids showing wind drift, drop, final velocity, final energy, and MV sensitivity for different combinations of ballistic coefficients and muzzle velocities at a fixed range. Use it to understand how BC and MV affect trajectory performance and to identify optimal load combinations.
Inputs
Range: Distance to the target in yards.
Drag Model: G7 is generally better suited for modern boat-tail bullets. G1 for older flat-base bullets.
Drop/Drift Units: Choose between MRAD, MOA, or inches for displaying drop and drift values.
Energy Units: Choose between ft-lbs or Joules for the energy table.
Bullet Weight: Bullet weight in grains. Used for kinetic energy calculations.
Temperature: Air temperature in degrees Fahrenheit. Higher temperature = less air density = less drag.
Altitude: Elevation above sea level in feet. Higher altitude = less air density = less drag. Pressure is estimated using a standard atmosphere model.
Humidity: Relative humidity percentage. Higher humidity slightly reduces air density.
BC Range: Define the start, end, and increment for ballistic coefficients.
MV Range: Define the start, end, and increment for muzzle velocities in fps.
Grid size: Start must be below End and the increment positive. Each axis is capped at 50 steps (and needs at least 2), so a very small increment across a wide range will be limited.
Results
Wind Drift (10 mph): Shows drift at the specified range with a 10 mph full-value crosswind from 3 o'clock. Lower values (green) are better.
Drop: Shows bullet drop below the muzzle line. Lower values (green) mean less drop.
Final Velocity: Remaining velocity at target range in fps. Higher values (green) are better.
Final Energy: Remaining kinetic energy at target range in ft-lbs. Higher values (green) are better.
MV Sensitivity: Shows the drop difference between MV ±0.5% (1% total spread). Lower values (green) mean the load is less sensitive to velocity variations, making it more forgiving of inconsistent ammunition.
Each row represents a different BC, and each column a different MV. Color is scaled independently within each grid (green = best, red = worst for that metric), so the same color in two different grids is not comparable.
Simulation Details
Wind: Fixed 10 mph full-value crosswind from 3 o'clock (used for drift table only).
Launch: Horizontal fire from muzzle (no zero, no scope height).
Spin Effects: Disabled for simplified comparison.
Known Limitations
This list is not exhaustive. Additional limitations, errors, or inaccuracies may exist.
Trajectory Values Not for Real-World Dialing: The trajectory values shown are not accurate for dialing a rifle in the real world. This tool does not account for zero distance, scope height, and other factors, which are essential for accurate holdover calculations. These values should only be used for relative comparison between loads.
Comparative Only: This tool is for comparative analysis. Not intended for live fire trajectory predictions. Do not rely on these calculations for any purpose where incorrect data could be hazardous.
Full Disclaimers: See the
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