The Ballistic Chronograph app is for use with the Caldwell line of Ballistic Chronographs supporting a 3.5mm line-out serial port.

Users running iOS 7 or greater

• When prompted “Caldwell Ballistic Precision Chronograph” Would Like to Access the Microphone - select OK.
• Please ensure that Settings -> Privacy -> Microphone -> Caldwell Ballistic Precision Chronometer is enabled (Access Granted).

Running the app with the setting disabled will result in no shots being seen even though the app is showing it as connected.

Users running version 1.14 or greater

• When prompted “Caldwell Ballistic Precision Chronograph” Would Like to Access the Camera - select OK.
• When prompted “Caldwell Ballistic Precision Chronograph” Would Like to Access Photos - select OK.
• Please ensure that Settings -> Caldwell Ballistic Precision Chronometer -> Camera is enabled (Access Granted).

Chrono G2 users running 1.17 or greater

To enable Bluetooth in the app. In the Chrono Settings - set Bluetooth enabled. If prompted - Turn on Bluetooth to Allow "Caldwell Ballistic Precision Chronograph" to Connect to Accessories. Select Settings. Turn on Bluetooth.

If prompted - Bluetooth is not enabled. Enable Bluetooth to continue. In Settings - Turn on Bluetooth.

What’s New

Version 1.18

Version 1.18 contains the following changes/updates:
• Weather API updated. Weather conditions now provided by Weather Underground.
• Altitude (FT) text field added. Barometric pressure ASL returned if altitude is not 0.
• Grain to gram conversion applied to weight for muzzle energy in joules.
• Strike a Line now reads Strike a Line. (Line = 1IN).
• On Start - Stop button only becomes active after get conditions have completed.

Ratings and Reviews

3.1 out of 5
66 Ratings

66 Ratings

FletchersKid ,

Good functionality, needs a key improvement

I got the chrono for its innovative upside down design that avoids glare from sun. The Bluetooth function is a huge help and it was another key reason for buying the unit. One BIG improvement the app needs is to export a CSV file(s) of the shot strings. This would make importing data into spreadsheets really easy. If the CSV export were added, my rating would move from 3 to 5! Are you watching this, Caldwell?

lordmorgul ,

Works fine on iPhone6s (corded)

This works fine on iPhone6s with the cord plugged in. You must turn off Bluetooth (in the app! Not just your device settings!) before it will recognize a cord connected device, which is a bug the developers should fix.

Recorded data well, with the cord being removed and reinserted several times as we switched stations during the day.

Highly recommended, it is simple and works well to relieve the mundane effort from data recording. Took shot data at faster than one per second. Bright sunny day at over 95deg F. May not be the most accurate device, but seems good enough for my needs.

Jalisco83 ,

Chrono works as expected

I bought this to measure my reloads and this chronograph works great. Tripod is sturdy, whole unit and app works great. The only downside I would have to say is the app in which we can add brands of cartridges and bullet size. It does not want to add three digits for bullet size. It will use the first two digits only. For example if I would insert 0.224 it will show 0.22 and for 9mm I would but 0.355 it would put 0.36. Also the app will not add to and existing brand. If I wanted to add Federal brand of cartridge it will create a new field. Also could add plated bullets brands or just played bullets to the app.


Battenfeld Technologies Inc
4.1 MB

Requires iOS 6.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Frequent/Intense Realistic Violence
Frequent/Intense Mature/Suggestive Themes


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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