![]() ![]() Windage and z-axis can mostly be treated the same. “Drop” at certain range is the distance that the bullet has fallen below the line-of-sight (or above if before zeroing range), but not the x-axis. For example, if the firearm is pointing 30° upward, 200m in range is only 173.2m away horizontally from the firing position. However, unlike x-axis, “range” on a range card is not the horizontal distance forward, but rather measured along the firing line-of-sight. Z-axis represents sideway distance, with shooter’s right being positive. Y-axis is pointing vertically upward, perpendicular to the ground and away from the earth center. Such a system is used in during MATLAB simulation, with x-axis pointing at the initial firing azimuth, parallel to ground (sea level). In a Cartesian coordinate, the x, y and z axes represent three directions perpendicular to each other. This section denotes to illustrate such differences to reduce any potential confusion by readers.įigure 1: Relationship between X, Y, Z and Range, Drop, Windage Two types of bullet are simulated in this study: Hornady 6.5mm 140gr ELD-Match and M855 5.56x45mm NATO.Ĭompared to ordinary physics analysis, some terminologies used in ballistic studies, ballistic data published by manufactures and range cards output by ballistic calculators can look similar while denoting different properties. To compare against the 6-DOF simulation result with point mass trajectory, JBM Ballistics, a popular web-based ballistic calculator is used. A copy of the MATLAB code is provided alongside this document. The main MATLAB function for the simulation is ODE45. MathWorks MATLAB R2019a is the platform to perform the ballistic simulation numerically. With changes and optimization made for computer simulation. The 6-DOF model developed in this study is based on Ballistics: theory and design of guns and ammunition, by Carlucci and Jacobson (2008). revealing more details in the motion of a projectile that point mass methods cannot provide. a more accurate trajectory compared to point mass methods (6-DOF simulation as a more advanced ballistic calculator), and 2. This allows for two potential outcomes: 1. ![]() The 6-DOF method explored in this study models the entire projectile throughout the simulation. However, as its name suggests, it models the projectile as a simple point, neglecting its shape and attitude, leaving potentially significant aspects out of the equation. Such method requires limited computing power and only a few parameters input by the user. Most of today’s ballistic calculators are based on the method of point mass trajectory. This study aims to simulate projectile trajectories of firearms with a six-degree-of-freedom (6-DOF) model. = 6-DOF Simulation of Firearm Trajectoriesīy Ange (Phil) Du, Advisor: Dr. At the present time, EMAFD is working on the CFD data for the Hornady 6.5 mm ELD Match 140 gr.īelow, the work used for validation of the 6-DOF is presented. Aerodynamic data is obtained from the supersonic, transonic and subsonic range. Structural data (inertia’s) are obtained from a CAD drawing and aerodynamics data (Cd,Cl,Cm etc) are obtained from a very high definition CFD model. ![]() Due to the complexity and amount of aerodynamic data required this solution is only available on individual cases. ELR being defined as taking the projectile to its limiots within the transonic and subsonic range. EMAFD has developed a six degree of freedom (6-DOF) for more serious precision shooters that would like to have more accurate solution for Extreme Long Range (ELR). ![]()
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