ArrowTime Chrono vs Zero Considerations

Sound based chronograph uses the iphone's. microphones to compute arrow speeds at specified distances. App saves group info so you can track performance over time. Allows you to save your favorite bows and arrows and try different combos, then check the resulting speeds and consistency.

A ballistics calculator that reads the paper. Photograph your shot group and Zero Considerations gives you the exact clicks your turret takes to move point of impact onto point of aim. Everything that measures and calculates runs on your phone, with no signal. Your firearms, loads, photos and results never leave your device. The one part that uses the internet is the optional weather fill, which sends an approximate location to a weather service and stores nothing. Leave it off and the app never touches the network. SIGHT IN FROM A PHOTO • Shoot your group, photograph the target, and the app finds the target and the holes, measures the group against your point of aim, and gives the exact click adjustments for your turret. • 1,273 optic entries carry the makers' own click values, so the same scope in MOA and in MIL gets the right answer. • Scale comes from a printed target with coded corners that also squares up camera tilt, or from a store-bought target the app recognizes. Type a known span for anything else. A manual fallback always works. • Sighting in indoors? Proxy zero works out where to print at 25 yards so you should be on paper at 100. The app calls a proxy zero a prediction, because that is what it is. • If it is not sure it has your target, it shows you the photo and asks. It will not print a confident call it cannot stand behind. BALLISTICS THAT MATCH YOUR RIFLE • Drop, wind and energy in MOA, MIL or clicks. • Temperature, pressure, humidity and wind fill in from your phone, or type them yourself. • A wind dial you drag to your call, with optional compass capture. • Point-blank range and maximum ordinate. • Zero and true: from a photographed group at a known distance, back out your true muzzle velocity so your dope matches what the rifle actually does. KNOW YOUR OPTIC BEFORE YOU SHOOT • 540 reticle patterns drawn to the makers' published subtension sheets wherever the maker publishes the numbers, to scale, so you can see your real holdovers — and where one never did, the app says so on the reticle. • A suggested zero distance for each reticle, based on your load. • A mount and riser calculator that works out true height over bore from your rail and mount, offset optics included. Bore sight it, then confirm the zero on paper. SET UP YOUR RIGS ONCE • Save firearms, optics, mounts, loads and lasers as setups you reuse. • 852 firearms and 512 factory loads built in, or add your own. • Device loadouts: primary optic, offset, laser and irons on one rifle, each with its own zero. WHAT IT COSTS • One purchase. No subscription, no ads, no analytics, no account. For education and lawful sporting use. Always verify your zero and dope on paper before relying on them.