Simulation Tools
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ⓘ Preset values are illustrative estimates only — not verified ballistic data.
Mass and diameter are well-sourced; Cd values are G1-BC-derived approximations for simple shapes only.
Entries without a Cd require manual input.
Full disclaimer 
Enter values and click Calculate.
Run a calculation first, then save it to compare scenarios.
Projectile flight is simulated using a 2D point mass model integrated with RK4 (4th-order Runge-Kutta) at up to 50,000 time steps. Air density and speed of sound are recomputed at each step based on the projectile's current altitude using the ISA troposphere model, so drag changes continuously throughout the trajectory.
Air density ρ and speed of sound are evaluated at altitude y at every RK4 sub-step. The drag coefficient Cd is looked up by local Mach number M = v / SOS(y).
Direct fire (≤ 10°): Simulation stops at the first crossing of target elevation. If the target is above the firing point the projectile stops on the ascending leg; otherwise on the descending leg.
Indirect fire (> 10°): Always runs to the descending leg before checking target elevation. A warning is shown if the projectile cannot reach the target altitude.
Fixed Cd — constant drag coefficient for the full flight. Useful for quick estimates or when no measured data is available.
Custom Cd curve — Mach vs Cd table, linearly interpolated. Enter pairs manually or paste two columns directly from a spreadsheet. If the projectile's Mach number exceeds the table bounds during flight, Cd is clamped to the nearest table entry and a warning is shown in the results.
Dynamic ISA — conditions are anchored at fire elevation. Temperature and density can be overridden with measured values; density scales with the ISA pressure profile above the firing point. Speed of sound is derived from actual temperature at each altitude.
Manual — fixed air density and speed of sound throughout the entire flight. Useful for matching CFD reference conditions or high-altitude scenarios where ISA is not representative.
Built-in presets are provided for orientation and quick exploration only. They are not a substitute for measured ballistic data and must not be used for any operational, engineering, or safety-critical purpose without independent verification.
Mass and diameter are sourced from publicly available technical specifications (manufacturer datasheets, military field manuals) and are generally reliable, though production lot variation exists.
Muzzle velocity is a representative figure for a standard barrel length and loading as noted per entry. Real-world values can differ by ±30–80 m/s depending on barrel, temperature, and propellant lot.
Drag coefficient (Cd) is the most uncertain value. Where provided, it is a constant approximation derived from a published G1 ballistic coefficient using:
A G1 BC is itself a compressed average of a full Mach-dependent drag curve. The conversion to a single Cd is therefore doubly approximate and cannot represent the transonic drag rise, where real projectiles typically see Cd peak at 1.5–2× the supersonic value.
Some projectiles have no drag value set. This is because no sufficiently reliable public data is available, or because the projectile operates across velocity regimes where a single constant Cd is not physically meaningful. For these entries you must supply your own value or Mach/Cd table.
Use measured or experimentally validated data whenever accuracy matters. A Mach-resolved Cd curve from Doppler radar, wind tunnel tests, or validated CFD is the correct input. If you have a manufacturer G7 BC, converting it to a Mach/Cd table and using the Custom Curve mode will give substantially better results than a fixed Cd for any rifle-class projectile.
The preset library will be updated as better-sourced data becomes available. If you find an error or have a verified source, please get in touch.