About

What is ballistics.foo?

ballistics.foo is an interactive web-based playground for learning about ballistics physics and modern web technologies. It combines a professional-grade ballistics calculation engine with a multi-language programming environment—all running entirely in your browser.

Whether you're a shooter curious about trajectory calculations, a developer exploring WebAssembly, or a student learning physics, ballistics.foo provides a hands-on environment to experiment and learn.

Features

Technology Stack

Core Engine:

The ballistics calculations are powered by the Ballistics Engine, a high-performance Rust library compiled to WebAssembly.

Language Runtimes:

Multiple programming languages run directly in the browser:

User Interface:

A clean, developer-focused interface built with:

Why WebAssembly?

• Performance: Near-native speed for complex calculations
• Portability: Run the same code on web, mobile, desktop
• Safety: Sandboxed execution with memory safety
• Language Agnostic: Call Rust code from any language

Who is this for?

🎓 Students and Educators

• Learn about projectile motion and aerodynamics
• Visualize how different factors affect trajectory
• Experiment with physics concepts interactively
• Understand drag coefficients and ballistic coefficients

👨‍💻 Developers

• Explore WebAssembly technology
• Learn how to call Rust from JavaScript, Python, Ruby, or PHP
• See real-world WASM performance benefits
• Study the open-source engine implementation

🎯 Shooters and Reloaders

• Calculate trajectories for different loads
• Understand wind drift and environmental effects
• Compare different bullet ballistic coefficients
• Learn about advanced ballistics concepts (spin drift, Coriolis)

🔬 Researchers

• Quick ballistics calculations for papers or projects
• Test sensitivity to different parameters
• Generate trajectory data programmatically
• Integrate into larger workflows via the API

The Ballistics Engine

ballistics.foo is powered by the Ballistics Engine, a professional-grade Rust library for external ballistics calculations.

Key Capabilities:

• Drag Models: G1, G2, G5, G6, G7, G8, GI, GS support
• Environmental Modeling: Temperature, pressure, humidity, altitude corrections
• Advanced Effects: Spin drift, Coriolis effect, aerodynamic jump
• Wind Modeling: Constant and variable wind profiles
• Zero Calculations: Automatic sight adjustments
• Energy and Momentum: Kinetic energy, momentum, recoil calculations

Physics Models:

The engine implements several ballistics models:

• Point Mass Model: Fast, simple trajectory calculations
• 4DOF Model: Four Degrees of Freedom with pitch damping and spin decay

Two Ways to Use the Engine

1. CLI-Style Interface

Simple command-line style interface. Great for quick calculations and demos:

const ballistics = new ballisticsEngine.WasmBallistics();
const result = ballistics.runCommand(
  "ballistics trajectory -b 0.505 -v 2789 --drag-model G7 -r 600"
);
console.log(result);

2. Object-Oriented API

Fluent API with method chaining. Type-safe and developer-friendly:

const calc = new ballisticsEngine.Calculator()
    .setBC(0.505)
    .setVelocity(2789)
    .setDragModel('G7')
    .setWind(10, 90)
    .setZeroRange(200);

const result = calc.calculateTrajectory(600);
console.log(`Drop: ${result.drop_inches}" | Drift: ${result.drift_inches}"`);

Safety and Responsible Use

Please review our Safety Disclaimer before using ballistics calculations. Key points:

• All calculations are mathematical estimates
• Real-world results vary due to many factors
• Verify all data independently in safe, controlled conditions
• Follow all firearms safety rules and regulations
• Comply with all applicable laws in your jurisdiction
• Seek professional training and advice

See our Terms of Service for complete legal terms.

Project Background

Why ballistics.foo?

This project was born from the intersection of three interests:

1. Ballistics: A fascination with the physics of projectile motion
2. Rust and WebAssembly: Exploring modern web technologies and performance
3. Education: Making complex physics concepts accessible through interactive tools

Traditional ballistics software often requires desktop installation, has outdated interfaces, or lacks educational focus. We wanted to create something that:

• Runs entirely in the browser (no installation)
• Provides instant feedback and experimentation
• Supports multiple programming languages
• Is fast, accurate, and open source
• Respects user privacy (client-side only)

Development Philosophy

• Performance First: Rust + WebAssembly for maximum speed
• Privacy Focused: All calculations run locally; we don't see your data
• Open Source: Transparent, auditable, improvable by the community
• Educational: Clear examples and documentation
• Accessible: Free, no accounts, works on any modern browser

Future Plans

Upcoming Features:

• 📊 Interactive trajectory visualization and charts
• 🎯 Ballistic coefficient estimation from measured data
• 🌡️ Expanded environmental modeling
• 📱 Mobile-optimized interface
• 📖 Comprehensive tutorial series
• 💾 Save and share calculations (privacy-preserving)
• 🔌 API endpoints for integration

Want to Contribute?

The ballistics engine is open source! Contributions are welcome:

• GitHub: github.com/ajokela/ballistics-engine
• Report Bugs: Open an issue on GitHub
• Suggest Features: Discussions and feature requests welcome
• Improve Documentation: Help make the project more accessible
• Submit Code: Pull requests for bug fixes and enhancements

Credits and Acknowledgments

Created By:

Alex Jokela - Developer, ballistics enthusiast, and Rust advocate

• Website: ballistics.rs
• GitHub: github.com/ajokela

Built With:

• Rust Programming Language - The foundation of the ballistics engine
• WebAssembly - Bringing near-native performance to the web
• Pyodide Project - Python in the browser
• ruby.wasm Team - Ruby runtime for WebAssembly
• PHP.wasm Project - PHP in WebAssembly
• Monaco Editor - VS Code's editor in the browser

Inspired By:

• Applied Ballistics - Professional ballistics research and education
• Bryan Litz - Pioneering work in modern ballistics
• The Rust and WebAssembly communities
• Open source ballistics software projects

Contact

Get in Touch:

Follow the Project:

• ballistics.rs: Main project website
• GitHub: Source code and updates

License

The ballistics engine is dual-licensed under your choice of:

• MIT License
• Apache License 2.0

Both licenses allow:

• ✅ Commercial use
• ✅ Modification
• ✅ Distribution
• ✅ Private use

See the full license text for details.

The website content and design are © 2025 Alex Jokela.