I have seen mention of them being used as backups like small bore pocket guns but I am not sure why they arent used much except perhaps by putting in cartridge conversion cylinders so they can fire cartridges. Maybe cowboys are like alot of shooters and are more interested in shooting than loading at a match, and don't want the mess and time to reload a front loader? You might find more interest in cap and ball among CW reenactors or the National Muzzleloading Rifle Assoc, which holds matches for that particular type of handgun.