Barrett transferred to the 5th Gurkha Rifles in 1882 and, having been promoted to captain on 10 September 1886, he took part in the Miranzai operations and the Hunza-Naga Campaign.
Barrett transferred to the 5th Gurkha Rifles in 1882 and became adjutant of the Calcutta Volunteers in 1886, although he also took part in the Hazara Expedition of 1888. He returned to the Gurkhas in 1891 and took part in the Miranzai operations and the Hunza-Naga Campaign.