Danny, the only specific reference to Bridges' sharpshooter battalion in action that I've found so far is in a report by Col. S. W. Ferguson, commanding "Detachment", describing a skirmish on Deer Creek, Mississippi, on March 20, 1863. In this account, Bridges' battalion appears to be a dismounted unit (though he never says so specifically), because Colonel Ferguson wrote about sending in "the cavalry", followed by "the sharpshooters". That's all I've found so far, but the search goes on.