The weaponry was discovered during a search on Saturday
Gardai are questioning two men over the seizure of guns and ammunition in Dublin.
The men, who are are both aged in their 30s, were arrested as part of an ongoing operation by the Drugs and Organised Crime Bureau, assisted by National Units.
One of the men was arrested after a car was stopped on the Naas Dual carriageway shortly before 3pm today.
The car was searched and a firearm and ammunition were recovered - a man in his 30s was arrested.
Shortly afterwards, a second car was stopped on the Long Mile Road in Dublin - the driver in his 30s was arrested.
Both men are being detained under section 30 of the Offences Against the State Act in Dublin Garda stations, where they can be held for up to 7 days.
Gardai say their investigations are on going.