I used to shoot competitively in IDPA and I've always wanted to try doing it on horseback - but not on Bobo! I came close to buying a gelding that was used in mounted shooting a few months ago and still wish I did. One day I'll give it a try.
The ammo used is made to shoot a distance of only ~20' and at competition, you have to use the ammo supplied by the organization - not your own. Doing it that way makes it safe for everyone. It is not a single projectile such as a bullet but rather something similar to bird shot.