The Ball caliber 2050 is a 49 jewels Swiss made automatic watch movement, based on an ETA 2824-2 with a Dubois Depraz chronograph module. It is said that the base is not actually an ETA 2824-2, but rather a Soprod P024 (ETA 2824-2 clone).
Not based on ETA caliber 7750:
You may find other sites incorrectly listing the caliber 2050 as being based on the ETA caliber 7750. It’s not uncommon for folks to automatically assume any Swiss made automatic chronograph is based on the 7750 framework. However, the Ball calibre 2050 is actually based on the ETA 2824-2 framework with a Dubois Depraz chronograph module added to it.
Dubois Depraz Module:
The Cannonball watch that uses this movement has some features that make it different from other timepieces that use the DD module. For example, the subdial at 9:00 is a 45 minutes counter. Most DD chronographs will have a 30 min subdial. Also, the Cannonball is bicompax with only two horizontal subdials and does not have a 12 hour counter at 6:00.
The layout looks more like a vintage Tudor powered by an ETA 2892-A2 with a DD 2054 module. The only issue there is that those have 55 jewels instead of the 49 jewel count on the 2050.
Ball has never really been transparent about their movements. This caliber listing will be updated as more information is discovered.
Updated caliber number:
This caliber has been replaced by the Ball caliber RR1401.