Ballistic Solver
Definition
Software (JBM Ballistics, Strelok Pro, Hornady 4DOF, AB Quantum) that computes trajectory accounting for drag, BC, muzzle velocity, and atmospheric conditions. Supplementary to official tables in court.
- Field
- Forensic trajectory reconstruction
- Example software
- JBM Ballistics, Strelok Pro, Hornady 4DOF, AB Quantum
- Inputs
- Drag, ballistic coefficient, muzzle velocity, atmosphere
- Court status
- Supplementary to official tables
Common questions
Why isn't a ballistic solver's output treated as conclusive in court on its own?+
A solver's trajectory calculation depends on its input parameters, such as the ammunition's actual muzzle velocity and ballistic coefficient and the atmospheric conditions at the time, and small errors in these inputs compound over distance, so courts generally expect the output to be corroborated against published ballistic tables or test firing data.
What is the practical difference between a solver like Hornady 4DOF and a basic point-mass calculator?+
Point-mass solvers model drag and gravity along a simplified trajectory, while four-degree-of-freedom solvers additionally model the bullet's spin drift and gyroscopic behaviour, which improves accuracy at longer ranges and for cases where precise lateral deviation from spin matters to the reconstruction.
Can a ballistic solver account for an unknown or uncertain muzzle velocity?+
Most solvers require a specific muzzle velocity as an input and will not automatically account for uncertainty in that figure, so where the actual muzzle velocity fired is not confidently known, analysts typically run the solver across a plausible range of velocities to bound the resulting trajectory estimate rather than relying on a single output.
Related terms
- Battle-Sight Zero (BZO)
- The zero range selected by a military or paramilitary organisation as the standard setting for field use. US Army M4: 300 m....
- Bore Axis
- The centreline of the barrel through which the bullet travels. The starting reference line for measuring gravity drop and the elevation difference...
- Gravity Drop
- The vertical distance a bullet falls below the bore axis at a given horizontal range, accumulating continuously from the instant of muzzle...
- Near-Zero Crossing
- The shorter of the two distances at which the bullet's trajectory intersects the line of sight. For a rifle zeroed at 300...
- Point-Blank Range (PBR)
- The maximum distance at which the bullet stays within the vital-zone radius above or below the line of aim without the shooter...
- Trajectory Rod
- A rigid fibreglass or aluminium rod inserted through a bullet wound channel and aligned with the channel geometry to define the bullet's...
- Vital Zone
- The defined target area used to compute point-blank range. For human thorax: typically 20 cm diameter (10 cm radius) centred on the...
- Zero Range
- The horizontal distance at which the bullet's trajectory crosses the line of sight. At this range, the point of aim and point...