Found some deserter information in the Police Gazette for 16 January 1880:
Born London, a labourer aged 27 2/3, 5' 5", lt brn hair, grey eyes, fresh complexion, deserted in Jersey 14 Dec 1879, off furlough. Moles over right hip and leg.
It's possible that he understated his age when joining the army in early 1871, in order to sign on as a boy soldier (not otherwise meeting the height requirement for a soldier).