Emergency services were powerless to help the victim after the younger man shot him in the face, newspaper Le Matin reports.
The assailant left the rifle at the crime scene and walked towards the centre of the village. He then called the police and was arrested shortly afterwards.
Initial investigations have shown that the two men, who lived next door to each other, began quarrelling on Saturday afternoon.
The 47-year-old man had received a notice of eviction from the owner of the flat where he had lived for a year. A police spokesman said the involvement of the victim in the future eviction of the assailant could have sparked the argument between the two.
Both men lived alone, although the 69-year-old was separated and had children.
The Neirivue episode is the latest in a series of deaths involving firearm to have taken place in Switzerland in the last few weeks.
A 23-year-old man died on November 14th in Boudry, canton Neuchatel, after a friend of his pulled the trigger of his military rifle in the mistaken belief that it was an air gun.
Ten days earlier, in Saint Leonard, canton Vaud, another military weapon was used in the killing of a 21-year-old woman. Her 23-year-old boyfriend is in prison awaiting trial.