Applied Ballistics has been providing custom drag models for use in trajectory prediction for the past several years. Custom Drag Models (CDM’s) for bullets are a more refined way of modeling drag for bullets because you’re not referencing a standard like G1 or G7, rather you’re using the actual measured drag of a specific bullet in a ballistic solver. This results in more accurate trajectory predictions especially thru transonic.
Although the benefits of this approach to modeling drag sound obvious, many questions have arisen as to how the custom drag models are different from BC’s, and what it all means. In this article, we start at first principles and build an understanding of how drag is modeled as a force, and how that’s applied in ballistic solvers to arrive at highly accurate ballistic predictions. Finally, the article concludes with some real world examples of how accurate ballistic trajectories can be in the real world when using CDM’s in the Applied Ballistics solver.
This article appears as Chapter 10 in Modern Advancements in Long Range Shooting – Vol 2.
Custom Drag Model Article
Applied Ballistics has measured and characterized the BC’s and drag models for over 735 modern bullets. The BC, stability and dimensional data for all these bullets is published in Ballistic Performance of Rifle Bullets – 2nd Edition. All of this bullet data is also available in a digital library for use with the Applied Ballistics programs. You can click here to view a listing of all the bullets currently contained in these libraries. AB Bullet Library Version 738 (2017)
Historically, one of the biggest challenges of calculating accurate trajectories was properly modeling the aerodynamic drag of bullets. Applied Ballistics ongoing live fire research in this area has elevated the state of the art by reducing the uncertainty in this area.
In summary, the measured CDM’s provided by Applied Ballistics have increased the accuracy of ballistic solvers. These CDM’s are available for all 735+ bullets in the AB library, and run on the various platforms and devices which run the AB program. This is the state of the art, in your hands.