Zeryn Precision
Rifle dope you can trust
Free
The precision data app that doesn't assume you own a $5,000 rig. Rimfire to long range, scopes or irons — set up in five minutes, dial with confidence.
Dope you can trust — whether you shoot a $400 rimfire with iron sights or a custom rig at 1,000 yards.
Zeryn Precision is a data app built by shooters, for shooters. It replaces the notebook, the shoebox of range cards, and the guesswork with one place that tracks your rifles, your loads, your groups, and your barrel — and teaches you every concept along the way. Precision doesn't have to cost a fortune.
YOUR RIFLES, SET UP PROPERLY
Add your rifle and optic once — about five minutes. Scopes or open sights: blade, aperture, globe, ghost ring. Zeryn takes iron sights seriously, so your lever gun gets the same treatment as a match rifle.
DOPE YOU CAN DIAL
Zeryn builds a full dope table for your rifle and load — drop, wind, spin drift — in MOA or mils, out past 1,000. Then True Your Dope: tell it where your shots actually landed and it corrects the table to match your rifle in the real world. Book numbers get you close. Trued dope gets you hits.
QUICK DOPE
No profile yet? Pick a caliber and a factory load and get a working table in seconds — honest about its limits, with a clear path
to a trued profile when you're ready.
FIND WHAT YOUR RIFLE LIKES
Run a factory ammo shootout: pick contenders from a library of 1,500+ factory loads, shoot a group per ammo on any target you like, and log the numbers. Zeryn picks the winner and graduates it into a Load — dope table and all. Stop buying bulk before you know it shoots.
BUILD YOUR HANDLOAD
Full load development workups — charge ladders and seating-depth steps. Shoot your steps on any target, log your groups and ES/SD, and graduate the winning node into a Load. Custom projectiles are welcome, with a BC estimator for when the box doesn't tell you.
WATCH YOURSELF GET BETTER
Log groups, browse your group history, and track your barrel over time — round counts and throat erosion — so you see accuracy trends and plan the rebarrel before it costs you.
WE TEACH AS WE GO
This is the part other apps skip. Every info button in Zeryn explains the concept in plain words — barrel length, sight height, twist rate, focal planes, turret travel — like a mate at the bench, not a physics lecture. A reference library covers BC, throat erosion, jump to the lands, reading wind, and estimating velocity without a chronograph. If you've ever bounced off a ballistics app because it assumed you already knew everything, this one was built for you.
WHO IT'S FOR
New shooters welcome. Iron sights welcome. The .22 you plink with on weekends counts just as much as a match rig. Rimfire to ELR, hunting rifles to long-range rigs — if you put rounds on paper and want them closer together, Zeryn is for you.
Zeryn Precision is free.
No account required. Your data stays yours.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Tidied up the home screen. The backup buttons only worked in the web version, so they've been removed from the phone app.
The developer, Trent Dunn, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- User Content
- Identifiers
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Trent Dunn
- Size
- 49.8 MB
- Category
- Sports
- Compatibility
Requires iOS 16.4 or later.
- iPhone
Requires iOS 16.4 or later. - iPad
Requires iPadOS 16.4 or later.
- iPhone
- Languages
- English
- Age Rating
13+
- 13+
- Frequent
Guns or Other Weapons
- Copyright
- © 2026 Trent Dunn