The jawan was identified as Ravindra Kumar, a sepoy in Army's 22 Rashtriya Rifles unit posted at Sopore in north Kashmir's Baramulla district.
Kumar was detained by the police at the airport after two bullets of an AK assault rifle were recovered during an X-ray check.
Kumar, a resident of Chhattisgarh, was going on leave and was to board an Air India flight.
He is under detention and is being questioned, the sources said.