In Philippine service, Gregorio del Pilar retained her South Vietnamese armament, consisting of a single Mark 12 5"/38 caliber (127-mm) gun, a dual-purpose weapon capable of anti-surface and anti-air fire, mounted in a Mark 30 Mod 0 enclosed base ring with a range of up to 18200 yards yards; two twin Mark 1 Bofors 40 mm anti-aircraft gun mounts, four Mk.