Barr, also known as CT-41/14-0301, was a clone trooper lieutenant within the ranks of the Grand Army of the Republic and participated in the Clone Wars. During that conflict, he commanded the 2nd Platoon of Bacta Company, itself a part of the 327th Star Corps, and led his platoon in combat. He had authority over four squads, consisting of thirty-two soldiers and four medics.
Early on during the war, the 327th sought to extract intelligence from the memory stores of a Confederate tactical droid. To achieve this, they set a trap within a rocky canyon, creating a false information bunker that successfully drew the attention of the droid. Subsequently, the droid commanded its forces to assault the bunker, which triggered Barr and the 327th to launch a rear attack. They efficiently eliminated the droid's troops, while Jedi General Aayla Secura decapitated the tactical droid. Because the droid had not entered cyberostasis, its memory banks were accessible for intelligence gathering.
Later, he participated in the Battle of Felucia alongside Galle and Bly. When Order 66 was issued, Barr assisted in the execution of General Secura.