The weapon gun was seized during a planned search on Wednesday evening in Bingian Drive by the PSNI’s Terrorist Investigation Unit. (TIU).
A 49-year-old man was arrested on suspicion of five offences, including possession of a firearm with intent to endanger life.
A 38-year-old woman was arrested on suspicion of possession of a firearm in suspicious circumstances.
Both remain in custody at the serious crime suite in Antrim.