What is the Cowboy Mounted Shooting sport? The most important thing to know is that they shoot blanks! They ride horses through a set course and have to pop the balloons with the firing of the blank cartridge. They are scored on the time of the run with any balloon left standing at the end of the run costing them a 5 second addition to their run time. Please see the links below.
There is a “Wiki” page for a good description:
https://en.wikipedia.org/wiki/Cowboy_mounted_shooting
There are a couple of clubs that have purchased these systems and use them at their events:
The Colorado Mounted Thunder club
http://www.mountedthunder.com/
And the East Coast Outlaws club
The “parent” organization of it all is CMSA:
https://www.cmsaevents.com/home/
There are many local clubs nation wide: