15 weapons of various calibre were recovered near Rathcoole
Four men remain in custody after firearms and ammunition were discovered in Dublin.
It followed a garda operation targeting organised crime groups.
Three men, aged in their 40s and 50s, were arrested Tuesday when gardaí discovered firearms and ammunition at Greenogue Industrial Estate in Baldonnel.
They recovered 15 firearms - including a number of revolvers and semi-automatic weapons.
One sub-machine gun and one assault rifle were also seized.
Some 1,300 rounds of assorted ammunition were also discovered - as well as a "substantial amount" of cash and documents relating to bank accounts.
A fourth man, aged in his late 30s, was arrested Tuesday evening at another location in Dublin.
All the men are being held at garda stations in west Dublin under Section 30 of the Offences against the State Act.