Thomas Doyle, 60, said he suffered noise induced hearing loss because he attended regular shooting practice.
The ex-sergeant attended shoots between July 2007 and his retirement, when he and colleagues were firing Heckler and Koch MP7 carbine rifles.
He was provided with conventional ear muffs and ear plugs and both were to be worn during shoots involving MP7s. But the ear muffs regularly became dislodged.
Mr Doyle launched an action against the Advocate General for Scotland, the law officer representing the MoD, at the Court of Session and has been awarded £4038 in damages.