The home of the elderly mother of a man involved in the Limerick feud was targeted with automatic gunfire this week.
Shots were fired by a lone gunman at the house in Canon Breen Park, Thomondgate, at 9.40 p.m. on Wednesday night.
Gardaí later recovered a loaded M57 automatic pistol in a nearby garden in de Valera Park.
A used cartridge was also recovered at the scene and was last night being examined by Garda forensic experts.
"No one was injured in the incident. However, the house was occupied at the time," a Garda source said.
It is thought the shooting was carried out in retaliation for a number of attacks over recent days in which windows were smashed at three houses in the Kileely and the Moyross areas.
The recovery of the automatic weapon comes just 24 hours after gardaí discovered an arsenal of weapons at a house in Mungret on the outskirts of the city.
The Minister of State, Mr Willie O'Dea, yesterday praised Limerick gardaí for their recent success in combating criminal activity related to the feud.
"Gardaí in Limerick are doing an outstanding job at keeping the situation under control.
"Their ongoing surveillance operations have proven to be very successful, and it's clear they are working on this around the clock," he said.
"They have identified possible targets and notified them of impending threats which has undoubtedly saved lives," the Minister said.