OneZero Ballistics Calculator vs LoadBench

Zero your rifle with one load and know exactly where a second load will hit, without touching your sights. OneZero is a ballistic calculator for 139 cartridges, from .17 HMR to .50 BMG. Use it for supersonic and subsonic .300 Blackout, a match load and a hunting load, or any two rounds you shoot from one zero. SEE THE SHIFT • Pick a zeroed round and a Round 2, and both fly from the same zero. • The headline shows where Round 2 lands at your distance and the hold to correct it: "12.3 in low · Hold U 11.7 MOA". • The solution updates live as you type. No Calculate button. READ DOPE AT ANY RANGE • Drag across the trajectory chart for drop at any yard. The readout stays put when you lift your finger. • Pinch to zoom, and switch between drop and drift. • The dope card lists up, down, left and right corrections for both loads, plus the shift between them, in MOA or MIL. 4,266 FACTORY LOADS BUILT IN • Pick your rifle's cartridge and browse its factory loads, with published ballistic coefficients and muzzle velocities. • Many include bullet length for stability and spin drift, and a G7 ballistic coefficient where the bullet has one. • Search or filter supersonic and subsonic, then tap a load to use it as your zeroed round or Round 2. WIND FROM YOUR COMPASS • Use Current Weather fills in the wind's speed and the direction it blows from. • Tap Target Direction and point your iPhone at the target, and OneZero works out the wind's clock direction. You can still pick it by hand. ON YOUR WRIST • The Apple Watch app shows the elevation and windage holds for both rounds from your iPhone's setup. • Turn the Digital Crown to step through distances 5 yards at a time. • The windage holds follow the watch's compass, so you can face the next target and read the hold. • Today's sunrise and sunset sit beside the clock, and your setup stays on the watch when your phone doesn't. PHYSICS YOU CAN CHECK • Standard G1 and G7 drag tables indexed by Mach number, the same reference data used by established ballistic solvers. • Air density from station pressure, temperature and humidity, with density altitude and speed of sound shown. • Wind from any direction: crosswind drift by the lag-time method, and head and tail winds in the drag. The wind's clock direction is picked by hand or worked out from compass bearings. • Miller stability and spin drift from your cartridge's bullet diameter, bullet length and barrel twist, corrected for muzzle velocity and air density. • Coriolis from your latitude, with its vertical part for the target's direction. MADE FOR THE RANGE • Use Current Weather fills temperature, humidity, pressure, altitude and wind from Apple Weather for your location. • Save rifles and loads as presets and switch between them in a tap. • Share a PDF dope card with both loads, ready to print. • On iPhone Duo, see Setup and the live solution side by side, split at the fold. • Dark mode and full VoiceOver support. Always confirm your dope with live fire before relying on it. Weather data provided by Apple Weather.

Every reloading app can log components. LoadBench helps you find the perfect load. Stop the frustrating guesswork of load development. LoadBench is a powerful analysis tool designed to guide you through the process of finding your firearm's most accurate and consistent recipe. We go beyond simple record-keeping to help you visualize your results and make data-driven decisions. VISUALIZE YOUR PERFECT LOAD: This is what sets LoadBench apart. Our app is built around the core tasks of load development: Powder Charge Testing: Easily log every shot across a range of powder charges. LoadBench then calculates the velocity statistics (SD, ES) for each charge, allowing you to visually identify the "node"—the charge that produces the most consistent muzzle velocity. Seating Depth (OAL) Testing: Systematically test different seating depths and record your group sizes. Our interface lets you visually compare the accuracy results to find the OAL that produces the tightest groups for your firearm. Instead of hunting through a notebook, you can see clear, side-by-side comparisons that make your best load combination obvious. ORGANIZED BY FIREARM: Every test and every piece of data is tied to a specific firearm. Optimize loads for your entire collection and easily access your "favorite" and most accurate recipes for each gun. COMPREHENSIVE LOGGING SUPPORT: Of course, we have the essentials covered. Log all your components (bullets, powder, primers, brass), environmental conditions, and detailed notes to support your load development process. INTEGRATED BALLISTICS CALCULATOR: Once you've found your perfect load, use our built-in calculator to analyze its downrange performance. Compare trajectories and understand the capabilities of your optimized handloads before you go to a match or a hunt. YOUR DATA, SECURE & PRIVATE: We believe your data is yours alone. All of your reloading and firearm information is encrypted at rest on your device for the utmost privacy. For users who want to analyze data on a computer and log at the range, our optional premium subscription offers multi-device syncing. This service is built with end-to-end encryption, meaning no one but you can ever access your data—not even us. Stop just logging data. Start using it. Download LoadBench and take the guesswork out of precision reloading.