Uphill and downhill shots, a card for every target, and BC truing at the range. • Shot angle: enter how steeply you're shooting up or down under Conditions, or point your iPhone at the target and Set Target Direction takes the angle with the bearing. Holds are worked out along the line of sight, as your rangefinder reads it. • Targets: a new tab for the targets you'll shoot at, each with its distance, angle and direction and both loads' holds. Give a target a direction and, with Wind From set, it gets its own wind clock. Aim your iPhone at a target to fill in its direction and angle. • Apple Watch: swipe left for your targets and their holds. Set up your shooting lanes before the hunt, and when your buck steps out the hold is on your wrist. Add or change a target with the Digital Crown and the watch's compass, and it goes to your iPhone too. • True BC: add the groups you fired past your zero (the elevation you dialed, where each landed, and your chronograph velocity) and OneZero works out the ballistic coefficient that fits them, and how firmly they pin it down. Use it in Setup, or save it to your load along with its groups.

More on your wrist, and room for a single load. • Apple Watch: tap a round's hold and turn the Digital Crown to change its muzzle velocity, say to match your chronograph. Tap the wind in the corner to set its speed and where it blows from, or face into it and tap Wind From Here. Changes go to your iPhone too. • Apple Watch: turn on Weather Updates and the watch fetches the weather where you are every 15 minutes while it's open. Wind you set yourself stays until you choose Use Weather Wind. • Apple Watch: swipe left for the setup. The info button is gone. • Only shoot one load? Turn off Compare a Second Round. The headline, dope card, PDF and watch show its velocity, energy and time of flight in place of Round 2. • The dope card shows each windage hold under its elevation hold, so there's no switching tabs, and the headline adds time of flight. • The trajectory chart has axis titles. • OneZero now runs on iOS 18 and watchOS 10 or later: iPhone XS and later, and Apple Watch Series 4 and later.

OneZero now uses your compass for wind. • Use Current Weather now fills in the direction the wind blows from as well as its speed. Tap Target Direction, point your iPhone at the target, and OneZero works out the wind's clock direction. You can still pick it by hand. • On Apple Watch, each round's windage hold now sits under its elevation hold and follows the watch's compass, so you can face the next target and read the hold. The info button moves to the bottom-right corner. • Headwinds and tailwinds now count too. They change the drag, so the drop: a 20 mph headwind lowers a 220 gr subsonic round almost 2 inches at 300 yards. • Coriolis: with your latitude, which Use Current Weather fills in, holds include Earth's rotation, about 3 inches each way at 1,000 yards at 45°. With the target's direction they include its vertical part too, and on Apple Watch they follow the way you face. • Stability now accounts for muzzle velocity and air density, as Miller's rule intends. Subsonic loads read less stable than before, with less spin drift, and thin air at altitude steadies a bullet. • 139 cartridges, up from 66, and 4,266 factory loads, up from 3,891. • About 500 more factory loads now include bullet length for stability and spin drift, and about 250 more have a G7 ballistic coefficient.

300BLK Dope is now OneZero: one zero, every load, for 66 cartridges. • Pick your rifle's cartridge in Setup, from .17 HMR to .50 BMG. Its bullet diameter feeds stability and spin drift. • 3,891 factory loads built in. The Factory Loads page opens on your rifle's cartridge, and you can browse any other. • New Apple Watch app: the holds and drops for both rounds from your iPhone's setup. Turn the Digital Crown to step through distances a yard at a time. Today's sunrise and sunset sit beside the clock, and your setup stays on the watch when your phone doesn't. • Made for iPhone Duo: open it to see Setup and the live solution side by side. The Solution tab puts the headline and a larger trajectory chart beside your dope card and details, split at the fold. Closed, the controls sit along the side so your dope gets more of the screen. • Switching between Light and Dark appearance now takes effect right away. • A smaller Setup title on iPhone leaves more room for your rifle and loads. • New setups default to a 10-yard dope card step. Your current setup and saved rifles carry over as .300 AAC Blackout.

300BLK Dope 2.0 is a complete redesign. • See where Round 2 hits: a new headline card shows the impact shift and the hold to correct it. • Live results as you type. No more Calculate button. • Drag across the trajectory chart to read dope at any distance, with a drift view and pinch zoom. • Dope card with up, down, left and right corrections in MOA or MIL. • Wind drift from a clock-face direction, plus spin drift. • More accurate ballistics: standard G1 and G7 drag tables, with air density from station pressure and humidity. • 134 factory loads from 26 makers, with corrected data. • Pick your rifle and rounds right from Setup. • Use Current Weather now fills wind speed too. • New app icon.

• New factory load: HSL Ammunition .300 BLK 220gr Subsonic • Corrected bullet length specifications for Phantom Defense Big Brother Rex • Bullet length is now an editable field when creating or editing load presets • Improved speed-of-sound calculation accuracy in humid conditions • Performance, reliability, and code quality improvements

G1 and G7 drag models — choose independently for each round Spin drift and stability — enter bullet length to calculate Miller stability factor and Litz spin drift, shown in results, dope table, chart, and PDF Interactive trajectory chart — pinch to zoom, drag to pan, double-tap to reset Factory ammo library — 64 loads from 14 manufacturers with bullet lengths included, browse, search, filter, and load directly Exportable dope card PDF now includes spin drift data Negative temperature input for cold-weather shooting Auto-select text on tap for faster editing