A Vietnam veteran who pulled a gun on two guests at a baby shower has been found not guilty of threatening to kill them, after telling the jury that his military instincts kicked in.

Key points: Dispute started after a baby shower guest parked in a neighbouring driveway

Dispute started after a baby shower guest parked in a neighbouring driveway Attilio Cavuoto pulled an unloaded gun during an argument with two guests

Attilio Cavuoto pulled an unloaded gun during an argument with two guests Mr Cavuoto argued he went into "self-preservation mode" when he was threatened

Attilio Cavuoto, 68, who has maintained he only drew the weapon after being threatened by the men, teared-up in the ACT Supreme Court as the verdict was read.

He was accused of threatening to kill a man and his step-son, who were attending a baby shower in a neighbouring house.

The gun was not loaded.

The dispute arose after another guest at the baby shower parked in the driveway of Mr Cavuoto's son.

The woman hosting the party told the court Mr Cavuoto had abused and sworn at her about the car.

When Mr Cavuoto aimed the gun at her son, and later at her partner, she said she was terrified and was waiting to hear a gunshot.

But Mr Cavuoto maintained he had acted in self defence, and only went to get the gun after being punched in the head from behind.

"I got the gun out of the car because I was in self-preservation mode, and because my life was threatened," he said.

"The idea was for them to back away from me."

He told the court his military training had kicked in and he took the best means to defend himself.

"I was in the military for 20 years … I was in Vietnam for 12 months," Mr Cavuoto said.

"You do not easily forget."

He told the court he did not stand a chance against the two men.

"They said they would punch my f***ing lights out," he said.

He denied he was out for revenge or to teach them a lesson or wanted them to feel scared.

The jury took nearly two days to reach a verdict, after a week-long trial.