Sandor Bata, 73, had bickered with his allotment neighbour, Mick Willson, 62, for months over their gardening rubbish. Bata accused Mr Willson of throwing his waste over the garden wall into his allotment.
Birmingham Crown Court was told that the trouble had come to a head on 11 August last year when Bata discovered the remains of a dead clematis lying on the soil he had tended for 15 years.
During the ensuing argument outside Mr Willson's home in Netherall, Leicester, Bata claimed that Mr Willson, 62, threatened to hit him with a piece of wood. Bata denied murder and said he had used his semi-automatic pistol, which was kept in his shed, in self defence.
After the shooting, Bata caught a bus into Leicester and had a pint in a city centre pub before calling the police from a telephone box and asking them to come and get him. He was still carrying the loaded pistol in a plastic bag when he used his walking stick to flag down two patrol cars on their way to arrest him.
Later he told police that Mr Willson, a former football referee and swimming coach, had attacked him like a "crazy man".
Bata showed no emotion yesterday as the jury found him guilty of murder after little more than an hour's deliberation.
The pensioner, who has arthritis and chronic lung disease and is confined to a wheelchair, listened with special amplifying equipment as Mr Justice Butterfield said: "You armed yourself with a deadly weapon and used it with deadly effect against a neighbour who had done no more than put cuttings in the wrong place.
"It was a dreadful tragedy and a terrible offence for which I have no option but to imprison you for life."
He said he would read reports on Hungarian-born Bata before deciding on the minimum sentence he should serve.
The court heard that Bata, who fought for Hungary in the Second World War, came to England after opposing the Soviet Union in the 1957 uprising.
In the 1980s he took one of the 98 allotments behind Mr Willson's home and Mr Willson rented the plot adjoining his own garden a few years later, thus making the two men neighbours.
Bata told the court they had had a number of disagreements about the allotment and Mr Willson's rubbish.
"I told him not to put it near my greenhouse but he continued to do so. He used to tell me I was in his country and I could not tell him what to do."
He said he had only wanted to injure Mr Willson by shooting him in the shoulder and "if he had not moved towards me the bullet would have gone clean through. He would have lived. But he did move and the bullet went in his neck."
The court was told Mr Willson died instantly from the single shot. He was found by his wife, Jacqueline, lying face down with blood on his back.
Confessing to having the gun illegally, Bata said he had never fired it before and did not know if it would work or not. He claimed it was there for safety reasons.Reuse content